bluuebunny/crossref_metadata_2025 huggingface dataset:
The Growth of Streptococci in a Flowing Medium with Special Reference to Haemolysin Production
Authors: Pulvertaft R. J. V.
Published: May 2009

The culture of organisms in a stagnant liquid medium, which is the normal method employed when the products of their metabolism are studied, has obvious disadvantages. The medium is constantly varying in its constituents and physical characteristics; prominent variations are oxygen tension, pH, food supplies and surface tension, and growth phase of the organism. Experimenters are constantly occupied in preparing nutritive media bearing closer analogy to living tissue fluids; but strangely enough little attention has been directed to maintaining the dynamic conditions obtaining when infection takes place. Yet such conditions may greatly modify the metabolism and general pathological activity of the organism.
The Influence of Certain Dietary Supplements in Relation to the Calcium Requirements of Growing African Natives. II
Authors: Henderson John McAskill , Kelly Francis Charles
Published: May 2009

1. Of five experimental subjects—growing East African native boys—four proved to have definitely negative calcium balances on the diet in use at the Nairobi Prison, while the fifth was merely in calcium equilibrium.

2. The diet in question was found to be so low in calcium (0·32 grm. Ca per day) that the occurrence of negative balances is not altogether surprising.

3. These negative calcium balances became positive on the addition of calcium as milk or in a mineral mixture with or without cod-liver oil.

4. Cod-liver oil alone was not effective in bringing about any appreciable reduction of a negative balance.

5. Our findings showed that 0·43 grm. Ca daily was the maintenance requirement for the subjects under experiment. This figure is practically the same as that found by Sherman in a summary of work on white races.

6. On giving additional calcium in a mineral mixture it was found that after the maintenance requirement had been satisfied, as much as 50 per cent. of any excess might be retained. The calcium of milk, on the other hand, was found to be utilised more efficiently; the corresponding retention figure being over 70 per cent.

7. The influence of the various supplements on growth is briefly discussed.
An Analysis of the Influence of Irradiation by means of a Mercury Vapour Lamp upon the Health and Fertility of a Breeding Stock of Guinea-pigs and upon the Health of their Offspring during the First Six Weeks of Life
Authors: Petrie G. F.
Published: May 2009

The maintenance of a constant supply of healthy guinea-pigs is an important part of the work of laboratories which are engaged in the production of diphtheria and tetanus antitoxin. The subacute infective processes to which malnutrition predisposes enhance the effect of the test dose of toxin, with the result that irregular deaths among the animals under test render difficult the titration of the antitoxin. For this reason it is desirable that breeding stocks should be kept in suitable animal houses under the best hygienic conditions possible. This policy has been followed in the Serum Department of the Institute for many years; there have been comparatively few introductions of stock from outside sources, and within recent years special attention has been devoted to diet.
Contributions to the Experimental Study of Epidemiology: The Effect of Vaccination on Herd Mortality
Authors: Greenwood M. , Topley W. W. C. , Wilson J.
Published: May 2009

In several previous reports we have described the behaviour of communities of mice, submitted over long periods of time to the risks attendant on the epidemic prevalence of a bacterial infection. These communities have been recruited in ways varying both as regards the rate of immigration and the nature of the immigrants.
George Henry Falkiner Nuttall:(5 July 1862—16 December 1937)
Authors: Graham-Smith G. S.
Published: May 2009

Nuttall was born in San Francisco, California, on 5 July 1862; the second son of Robert Kennedy Nuttall, M.D. (Aberdeen) and his wife, Magdalena, daughter of John Parrott of San Francisco. The Nuttalls were descended from an old Lancashire family, which settled in Ireland in 1707, many of its members serving as officers in the British Army. His father went to Australia, but migrated to San Francisco in 1850 and practised there till 1865. In that year the family came to Europe and remained there till 1876, the children being educated in England, France, Germany and Switzerland. Consequently, Nuttall spoke several languages, a fact which assisted him enormously in his future work and travels.
The bacteriology of meat and fish pastes, including a new method of detection of certain anaerobic bacteria
Authors: Crossley E. L.
Published: May 2009

1. The bacteriological problems involved in the production of meat and fish pastes in sealed glass jars have been studied.

2. Data are presented showing the normal flora of the raw materials used. Particular attention is drawn to the anaerobic species present in seasoning materials.

3. Bacterial contamination due to manufacturing operations is discussed.

4. The requirements of a satisfactory heat treatment are outlined, together with experimental methods of study used to overcome possible causes of failure.

5. Bacteriological examinations of 14,365 samples of paste showed that 88% were sterile: the flora of the remainder was examined.

6. Experimental evidence is presented to show that certain anaerobic spore-forming bacilli are the main possible cause of spoilage, and the significance of aerobic spore-forming bacilli has been established. An extremely heat-resistant anaerobe was isolated.

7. Routine bacteriological control of the finished products is suggested.

8. A simple, inexpensive, and rapid method of detecting anaerobic species has been devised, which can also be applied to other foodstuffs. Data are presented from the examination of a further 6110 samples using this method.
Antipneumococcal species immunity
Authors: Downie Allan W.
Published: May 2009

In the experiments recorded the various antigens prepared from type I pneumococci failed to produce effective resistance in mice to heterologous types or to produce demonstrable antibodies against these types in mice or rabbits.
An ice-cream food poisoning outbreak due to B. dysenteriae (Sonne)
Authors: Savage William
Published: May 2009

An outbreak in May 1937 of about 130 cases of mild Sonne dysentery with no deaths. The outbreak was spread by ice-cream made under very unsatisfactory conditions, but no carrier case or specific source of infection ascertained. The very scattered nature of the outbreak, involving five different sanitary areas, with place of preparation in a sixth, is a feature of interest.
The effect of diet on epidemics of mouse-typhoid
Authors: Watson Marion , Wilson Joyce , Topley W. W. C.
Published: May 2009

In previous reports (Watson 1937 a, b) one of us has described a series of experiments in which various diets were tested in regard to their effect on the growth, fertility, survival and resistance of mice. It was found that, when part of the oatmeal in a particular diet was replaced by dried skimmed milk, the does were more fertile, and the young mice gained weight more rapidly and showed a lower mortality during the first 8 weeks of life. Mice bred and reared on the latter diet were found to show a significantly increased resistance to per os infection with living cultures of Bact. typhi-murium, and to the intraperitoneal injection of a toxic fraction derived from that organism. The results obtained in a few tests suggested that these mice were also more resistant to the intraperitoneal injection of living Bact. typhi-murium; but the differences observed were smaller, and of doubtful significance. In the present paper we record the effect of these two diets on the epidemic spread of mouse-typhoid.
Growth of Salmonella typhi and certain other members of the Salmonella group in milk and butter stored at atmospheric temperatures
Authors: Pullinger E. J. , Kemp Audrey E.
Published: May 2009

1. A technique for studying the behaviour of Salmonella in milk is described.

2. S. typhi, paratyphi B, dublin, cholerae-suis, typhi-murium, enteritidis and bovis-morbificans all multiplied readily even in absolutely fresh raw milk stored at 15°C., and in commercial grades of raw and of heat-treated milk rapid multiplication also occurred.

3. Strains of S. typhi recently isolated from man showed more rapid multiplication in milk than did stock laboratory cultures.

4. These Salmonella all survived at least 2 months when incorporated in various grades of salted and unsalted butter.
A Vi variant ofSalmonella typhiand its application to the serology of typhoid fever
Authors: Bhatnagar S. S. , Speechly C. G. J. , Singh M.
Published: May 2009

1. The description of a strain which behaves as a pure Vi variant ofS. typhiis given. Complete absence of H antigen from it is demonstrated. The non-interference in its Vi agglutinating activity by the very small amount of O antigen contained in it is shown. This strain has been designated “Vi 1”.

2. With the help of this strain, the practical applicability of Vi agglutination as a reliable method for the routine serological diagnosis of typhoid infection and for the detection of typhoid carrier condition, in preference to O and H types of agglutination, is stressed.
Two new Salmonella types isolated from fowls
Authors: Edwards P. R. , Bruner D. W.
Published: May 2009

Two new Salmonella types are described. S. minnesota was isolated from a turkey. Its antigenic formula is XXI: b ⇋ enx. S. worthington was found both in a chicken and in a turkey. Its antigenic formula is I XIII XXIII: Iw ⇋ z…. Transfers of each type have been deposited in the National Collection of Type Cultures of Great Britain and in the American Type Culture Collection.
The concentration of carcinogenic materials in mineral oils by distillation processes
Authors: Twort J. M. , Lyth R.
Published: May 2009

1. A range of commercial distillates of a topped crude Borneo, mineral oil were tested for carcinogenic activity and it was found that the peak was around a viscosity at 25° C. of 200 to 250 Centipoises.

2. The whole range of oils was biologically active. This activity had been foreseen from an examination of the physical characteristics, alone sufficient to condemn the utilization of any single representative as a lubricant when likely to come into contact with the user.

3. A greater concentration of the carcinogenic material was obtained by molecular distillation of oils than by ordinary distillation at from 3 to 10 mm.

4. The middle fractions of a Borneo crude oil were mostly responsible for pathological changes in the organs—fatty infiltration of the liver and hyaline degeneration of the spleen. These results again confirm previous findings.

5. Lung tumours were, according to our experience with mineral oils more prevalent than is usual when utilizing this type of agent for testing carcinogenicity for the skin. Their incidence was somewhat higher in the more viscous fractions but was not apparently related to their carcinogenicity for the skin.

In conclusion we should like to thank Dr C. C. Twort, former Director of this Department and now of the Portslade Laboratories, Sussex, for his helpful suggestions and advice in the compilation of this paper, and wish also to acknowledge their indebtedness to Dr J. R. Bowman of the Mellon Institute of Industrial Research, University of Pittsburgh, for a micro method of viscosity determination.
Diphtheria: A suggested explanation of the relative change in age incidence
Authors: Cheeseman E. A. , Martin W. J. , Russell W. T.
Published: May 2009

The purpose of the investigation was to examine the reason for the relative age shift in the incidence of diphtheria. The disease has been represented as now concentrating on children of school ages. We analysed, for various quinquennial periods beginning with 1901–5, the statistics of the notifications and deaths according to age and sex in the London boroughs which we classified into four social classes where I to IV represented descending order in the social scale. The conclusions arrived at were:

I. The age shift as represented by the ratio of the mortality at ages 0–4 to ages 5–9 years which has taken place in London has been found to occur mainly in the poorer districts. The ratio in the residential districts has not altered appreciably during the thirty years under review (Table V).

II. The age shift is also indicated by the morbidity statistics for the three quinquennial periods, 1901–5, 1909–13 and 1919–23, as there was a significant increase in the mean age of attack of children under 15 years of age.

The case rate at ages 5–14 during 1929–33 as compared with that in 1901–5 has increased most amongst children in the lowest social group.

III. Each of the variables (a) the decrease in the birth-rate between 1911 and 1931 in each London borough—an index of the change in the size of family—and (b) the decrease in infant mortality—a measurement of environmental improvement—is positively and significantly correlated with (c) the corresponding change in the size of the ratio of the case rates at ages 0–4 to 5–9 years. The coefficients were:

but the partial correlation coefficients

indicate that the change in the size of family is the more important factor as the value of rac.b is fairly large and significant, whereas the correlation between the change in the ratio and the environmental improvement when the effects of the decreasing birth-rate are made constant—rbc.a—becomes statistically unimportant.
Improvements in the globe thermometer
Authors: Vincent D. F.
Published: May 2009

The globe thermometer was designed by H. M. Vernon as a simple instrument that will give a more reliable measure of the comfort of a room than the ordinary wall thermometer. When the room is heated by some system of low-temperature radiation, such as hot-water pipes, and when the amount of air movement is not excessive, the globe thermometer is probably as good as any single simple instrument can be. But it has never come into general use because there are conditions under which its indications may be very misleading to the layman.
A note upon the maintenance of cultures of Bacterium typhosum for testing by the Rideal-Walker method
Authors: Coulthard C. E.
Published: May 2009

The British Standard Technique for Determining the Rideal-Walker Coefficient of Disinfectants (no. 541—1934), in laying down the procedure to be adopted with regard to the test typhoid bacillus culture, recommends that a fresh culture be obtained each month from the National Collection of Type Cultures. In all probability this is the best procedure; it does, however, sometimes happen that a test is required urgently when a fresh culture is not available. The following notes upon our own experience in maintaining cultures may therefore be of some interest. It is our practice to obtain fresh cultures whenever we are called upon to carry out other than routine tests unless a recent one has been obtained, and many of these cultures have now been running for a number of years. On the arrival of the culture from the N.C.T.C. it is subcultured on to an agar slope and “incubated” at room temperature in a dark cupboard. 2% agar is used in a broth prepared by the tryptic digestion of ox heart. Further subcultures are made at intervals of one month. It is our usual practice to start a series of broth cultures from such slopes not less than 14 days after sowing.
A slide agglutination test for the exclusion and diagnosis of typhoid fever
Authors: Berger F. M. , Brecher G.
Published: May 2009

A sensitive antigen suspension is described for use with a simple slide agglutination method which makes possible a serological diagnosis or exclusion of typhoid fever without recourse to a laboratory. The method has been tested on 414 sera sent to our laboratory; it detected all cases with a titre of 1: 80 or more, and most of those with a titre of 1: 40. The method was further tested on 130 clinically observed cases, in which it gave satisfactory results. The S. A. method gave a positive result with 98 out of 100 sera from patients with typhoid fever, whereas the classical Widal reaction gave a positive result with 68 of them only.

The intensity and rapidity of the slide agglutination reaction provide a rough measure of the titre of a serum. A quick and distinct agglutination indicates a titre of 1: 80 or more and is diagnostic of typhoid fever. A slow and indistinct result is obtained when the titre of the serum is about 1: 40. A negative test indicates with great probablity that a diagnosis of typhoid fever may be excluded.

We think the method succeeds because the nature of the suspension employed and the peculiar behaviour of slide agglutinations permit the detection of O agglutinins as well as H agglutinins.
The relationship of field rodents to plague in Kenya
Authors: Roberts J. I.
Published: May 2009

1. A study of the literature of East Africa on the incidence of plague in field rodents shows that in no single instance has evidence been offered to prove they have any relation to the disease.

2. Recent epizootics in field rats in Kenya are described.

3. The health of house and field rats is discussed, with an account of the work carried out on a septicaemic condition present in field rats.

4. The results of bacteriological examination of 2750 field rats and attempted transmission experiments with 1285 field fleas, both investigations conducted during a period when there was heavy mortality among them, failed to establish the presence of B. pestis.

At the same time, mortality among the Rattus population, proved bacteriologically to have been caused by B. pestis, enabled successful transmissions to be accomplished with fleas from that species.

5. In the absence of any confirmatory bacteriological evidence to prove that epizootics among field rats are caused by B. pestis, and the failure to find natural infection among field fleas, together with the knowledge of their aversion to feed on man and lack of opportunity to develop such tastes, the theories that field rodents and their fleas “are definitely assisting in the perpetuation and spread of plague” or that they “ are possible factors in initial outbreaks of plague” (Thornton, 1930) appear to be fallacious.

6. Plague in Kenya is distinguished by its isolated and sporadic nature, even in endemic areas, and it is not dependent on types of housing or the general hygiene of inhabited areas, but on individual domestic habits. Any individual, neglectful in regard to food, particularly its storage and wastage, is the person responsible for the disease, by offering an unlimited supply of food to a dense rat population and encouraging its survival.
Notes on typhus fevers in Kenya
Authors: Roberts J. I.
Published: May 2009

1. The history of a typical sanguineus-borne human case of typhus is given, together with the results of intraperitoneal inoculation of material from the initial lesion into guinea-pigs.

2. This material in the earlier inoculations caused a high mortality rate among guinea-pigs, and is characterized from the other material obtained from rats and fleas by the swing of temperatures between morning and evening.

3. Three cases of non-lesion typhus occurred in a brewery heavily infested with rats and fleas, the patients affirming they had been bitten only by fleas.

A high rat infestation was noted and a Xenopsylla index of 15·0 per rat.

4. Inoculation into guinea-pigs of emulsified brain and testicle material from Rattus rattus trapped at this typhus focus, and of emulsified fleas from the rats, resulted in the establishment of a strain of virus which produced a typhus-like syndrome in guinea-pigs.

5. Infection of guinea-pigs with strains of virus from rats, ticks and fleas, has been secured without any difficulty in Kenya, and it has not been found necessary to keep guinea-pigs on vitamin-deficient diets.

6. Typical scrotal reaction has been observed in the majority of guinea-pigs inoculated. The onset is generally sudden and coincides with the rise in temperature. Subsidence of the swelling and inflammation is gradual over about 3 days.

7. Loss in weight is not a marked feature of the forms of virus encountered in Kenya.

8. Post-mortem appearances in the rat-and flea-forms differ from those of the tick-type mainly in less ascites and slight enlargement of the spleen.
The reactions of streptococci and lactobacilli in blood agar
Authors: Davis J. G. , Rogers H. J.
Published: May 2009

The phenomena produced by colonies of streptococci on blood-agar plates have long been used by medical bacteriologists for classification purposes. An examination of the literature showed that only a few contradictory data were available for the corresponding phenomena induced by the saprophytic lactic acid bacteria. A systematic investigation into the types of “haemolysis” and discoloration phenomena produced by typed cultures of lactic acid bacteria was therefore carried out to ascertain whether the blood-agar plate was of any use in the routine classification of these bacteria. The monograph of Brown (1919), which has been generally accepted as the standard work on the subject, is regarded as a standard of reference in the present paper.
Further observations on the relation of the decline in the number of horse-drawn vehicles to the fall in the summer diarrhoea death-rate
Authors: Graham-Smith G. S.
Published: May 2009

Ten years ago the writer (Graham-Smith, 1929) called attention to the relation of the decline in the number of horse-drawn vehicles, and consequently of the urban breeding grounds of flies, to the fall in the death-rate from summer diarrhoea in children under one year of age.
The survival of the Calmette-Guérin strain of tubercle bacillus (B.C.G.) in the blood and mamma of goats
Authors: Griffith A. Stanley
Published: May 2009

Intravenously injected into a goat in a single dose of 50·0 mg. b.c.g. caused the death of the animal from pneumonia in 9 days and was demonstrated in the blood until the day of death, though in progressively diminishing numbers.

Intravenously injected into a goat on successive occasions, the dose on each being 10·0 mg., b.c.g. was filtered from the blood by the tissues within 3–5 days. There was little or no evidence that b.c.g. disappeared from the blood more quickly after previous injection of that micro-organism. b.c.g. was not excreted into the milk cisterns of this goat or, if excreted, the bacilli did not long survive.

Intramammarily injected b.c.g. produced inflammatory reactions in the mamma with formation of caseo-pus and ultimate destruction of the gland as a secretory organ. The micro-organisms, however, did not remain alive for any lengthy period in the mamma and in the two instances reported were not viable after about 15 weeks.
The susceptibility of the water (or grass) snake (Trepidonotus natrix) to the avian tubercle bacillus and to reptilian strains of acid-fast bacilli
Authors: Griffith A. Stanley
Published: May 2009

The joints of rabbits are predilection sites of disease in chronic avian infections and are nearly always found affected in rabbits which have lived longer than 3–4 months after an intravenous or subcutaneous inoculation of fully virulent avian strains. Highly attenuated avian strains, namely, those which have ceased to be infective for fowls, also give rise to joint disease in rabbits when injected intravenously; for example, twelve rabbits which lived over 5 months after intravenous inoculation of 2·5–10·0 mg. of attenuated avian strains all showed joint tuberculosis, and in eleven of these the joints were the only affected parts (Griffith, 1925).
An atypical Neisseria causing meningitis
Authors: Edwards J. L.
Published: May 2009

A pleomorphic, Gram-negative organism, apparently the cause of purulent meningitis, is described. Reasons for regarding it as a Neisseria are adduced.
Cytological observations onBact. coli, Proteus vulgarisand various aerobic spore-forming bacteria with special reference to the nuclear structures
Authors: Robinow C. F.
Published: May 2009

1. The basic observations of Piekarski (1937–40) and F. Neumann (1941) on Feulgen-positive, chromatinic structures, going through a regular cycle of division, in the cells ofBact. coliandProteus vulgarisare confirmed and the view that these structures are nuclear in nature is accepted.

2. The chromatinic structures in bacteria from old cultures, although usually distinguishable from the cytoplasm, are too small to be resolved accurately. After transfer to a fresh nutrient medium the chromatinic structures increase in size and give rise to short, often dumbbell shaped, rods (chromosomes) which multiply by splitting lengthwise in a plane more or less parallel with the short axes of the bacterium.

3. The chromatinic structures ofBacl. coliand ofProteus vulgarisare essentially the same as those previously described in myxobacteria and actinomycetes (Badian, 1930, 1933, 1936) and in various well-known aerobic spore-forming bacteria (Badian, 1933, 1935; Robinow, 1942).

4. A single cell ofBact. coliorProteus vulgariscontains one chromatinic body or one or two pairs of these, representing primary and secondary division products.

5. Few bacteria from young cultures are single cells. When fixed through the agar with Bouin's mixture and stained briefly with Giemsa's solution, bacteria from young growing cultures ofBact. coli, Proteus vulgaris, B. mesentericusandB. megatheriumassume a banded appearance indicating that each bacterium consists of two, three or four separate cells.

6. A plasmolysing treatment has been applied toB. megatheriumwhich provides direct proof of the composite structure of this bacillus by inducing its component protoplasts to shrink away independently from the outer supporting cell wall.

I wish sincerely to thank Dr H. B. Fell for the hospitality offered to me at the Strangeways Laboratory, for her sustained interest in this investigation and for her help in preparing the manuscript for the press. I have also pleasure in admitting my indebtedness to Prof. E. G. Pringsheim for much helpful criticism and advice in matters relating to the bacterial cell wall.
The influence ofSalmonella typhi-muriuminfection in rats on vitamin A metabolism
Authors: Kligler I. J. , Guggenheim K.
Published: May 2009

Since Green & Mellanby (1928, 1930) reported that vitamin A protected the body against infection, this problem has been studied by various authors (Verder, 1928; Lassen, 1930, 1931; Seidmon & Arnold, 1931–2; Boynton & Bradford, 1931; McClung & Winters, 1932; Stryker & Janota, 1941). In general, the results showed that A avita-minotic animals were more susceptible to spontaneous or experimental infections than controls kept on a normal diet. However, in so far as we know, no experimental work has been done on the inverse problem—the effect of infection on vitamin A metabolism.
Diphtheria in Hull: A Review of six years bacteriological typing
Authors: Leete H. Mason
Published: May 2009

This paper embodies the findings in all proven cases of diphtheria admitted to the Hull City Hospital during the years 1938–43 inclusive. All cases during those 6 years were typed and the clinical and bacteriological findings correlated. Since 1932 all severe cases had been typed and in the winter of 1932–3 a consecutive series of 313 cases was investigated and the results published (Leete, McLeod & Morrison, 1933). The 1933 paper showed a high gravis incidence of 59% and an associated high case fatality rate. Not until the end of 1937 was it again possible to type every case admitted but since then we have done so, and the series now presented embodies observations on 2039 infections, the great majority of which were clinical cases.
Note on the war-time health of women in industry and at home: A comparative survey
Authors: Wilson Dagmar C.
Published: May 2009

1. Clinical examination of 374 industrial women workers and 289 housewives of comparable type was made in Oxfordshire in August 1942 and repeated four times subsequently on the same groups up to March 1944.

2. It was concluded that the diet of these women was adequate to prevent obvious signs of vitamin deficiency but that there was a general tendency for the general nutritional state, assessed clinically, to deteriorate during the 19 months of this study. This deterioration was associated with complaint of fatigue.

3. The women workers residing in areas where the water was low in iodine content tended to show enlargement of the thyroid gland. The enlargement increased in those already affected, and the incidence also increased.

The author is much indebted to Dr J. O. Irwin for his assistance in statistical presentation of the data and to Dr Harriette Chick for helpful criticism.
Quantitative aspects of antigen-antibody reactions. II. Some comparisons between the theory and the experimental results
Authors: Teorell Torsten
Published: May 2009

The quantitative theory for the interaction between antigen and antibody presented in the previous paper has been compared with some experimental precipitin reactions published in the literature. These reactions include Type VIII pneumococcus polysaccharide-homologous (horse) antibody, egg albumin-(rabbit) anti-egg albumin and diphtheria toxin-(horse) antitoxin.

1. The general course of the experimental precipitation curves (total amount of precipitate, amounts of precipitated antigen and antibody) corresponded well to the theoretical type curves. Hence it may be concluded that the precipitates may be composed of mixtures of compounds of the typesAG, A2G, A3G, …,ANGin accordance with the law of mass action. In the cases with ‘inhibition zones’, however,AG, orANG, or both (and perhaps several more compounds) retain the same solubility as the free antigen(G)and free antibody(A).

2. With regard to the location of the ‘equivalence zones’, experiment and theory also showed a satisfactory agreement.

3. A hypothesis on the velocity of flocculation in the precipitin reaction is presented and compared with some recent results. The relation between the immunological concepts ‘equivalence (neutral) point’, ‘optimum point’ and ‘maximum precipitation point’ is also discussed.
Three rapid tests for the estimation of tropical fitness of fabrics
Authors: Koch Walter
Published: May 2009

Three major factors determine the tropical fitness of fabrics: (1) thermal insulation, (2) porosity, (3) reflecting power.
A photometric method for the comparative evaluation of disinfectants
Authors: Needham N. V.
Published: May 2009

1. Attention is called to the widespread dissatisfaction with the standard of reproducibility attained with the existing disinfectant tests.

2. It is suggested that this lack of reproducibility is inherent in any 100% mortality test.

3. The trend in all recent disinfectant developments appears to be towards greater specificity than was the case with the older products.

4. Where a comparison is being made to ascertain the true relative efficiency of two or more disinfectants, this possible specificity necessitates their examination under a wider range of conditions than has been catered for in the past.

5. A technique is suggested for use in those cases where a more limited examination will provide all the information that is required. It employs a simple culture medium, uses a measured quantity for the transfer from the medication tube, and makes use of a compensated photo-electric circuit to determine the amount of growth produced by the organisms which have survived the contact with the disinfectant.

I wish to acknowledge my grateful thanks to the directors of Messrs Cooper, McDougall and Robertson Ltd. for permission to publish this paper, and to my colleagues of the Cooper Technical Bureau for assistance in various directions.
Efficacy of protein hydrolysate in the restoration of serum protein in hyperimmunized horses after blood depletion
Authors: Basu P. N. , Nath Sen Sudhindra
Published: May 2009

1. Treatment with enzymic hydrolysate of protein after blood depletion has a significant action in restoring serum protein content.

2. Blood depletion of hyperimmunized horses alters the serum globulin fraction much more markedly than the serum albumin fraction.

Our thanks are due to Dr R. N. Roy and Mr Diptish Chakraborty for useful help.
The digestibility of English and Canadian wheats with special reference to the digestibility of wheat protein by man
Authors: McCance R. A. , Widdowson E. M.
Published: May 2009

1. Two men and four women carried out digestibility experiments on English and Canadian wheats at 90 and 80% extractions. The flour was the only source of protein and contributed 77−93% of the total dietary calories.

2. At 90% extraction the digestibility of the diets in terms of calories was unaffected by the source of the flour and amounted to 93·3%. At 80% extraction the digestibility of the diet containing English wheat amounted to 95·6% and of those containing Manitoba wheat to 96·7%. The difference is attributed to mild intestinal upsets on the English flour.

3. The apparent digestibility of the protein depended upon the amount of N in the wheat and fell as the extraction rose. A quantitative analysis of the results indicates that the protein in wheat flour of 90 and 80% extraction is completely digested and absorbed, and that the N found in the faeces is entirely derived from the secretions of the gut.

The Medical Research Council paid for the expenses of this investigation. We are very much indebted to Drs T. Moran, C. R. Jones and other members of the Cereals Research Station, St Albans, without whose help this study would hardly have been possible. We have also very much appreciated the help we have received from the subjects, Miss M. Costain, Miss C. M. Walsham, Miss E. Wilkinson and Mr R. Tayler, and also from Flt.-Sergeant Childs, who kindly made the bomb calorimeter determinations.
Sylvatic plague studies. The vector efficiency of nine species of fleas compared with Xenopsylla cheopis
Authors: Burroughs Albert Lawrence
Published: May 2009

All fleas used in this study were collected in the field and except for Pulex irritans were cultured in the laboratory. The ten species studied were Xenopsylla cheopis, Nosopsyllus fasciatus, Orchopeas sexdentatus sexdentatus, Opisodasys-nesiotus, Megabothris abantis, Malaraeus telchinum, Diamanus montanus, Echidnophaga gallinacea, Pulex irritans and Oropsylla idahoensis.

All fleas transmitted in individual feeding studies with the exception of the latter two species, which transmitted en masse. Echidnophaga gallinacea could not be fed periodically as were the other fleas because of its tick-like feeding habits. Consequently, the vector efficiency obtained for this species is not strictly comparable to that found for the other species.

The transmission data obtained from individual flea feeding studies was analysed statistically to estimate the expected number of transmissions per flea of each species. These values are obtained as intervals which have a 90% probability of containing the true value. The true vector efficiency of Xenopsylla cheopis was found to be 0·660 ± 0·234 (expected transmissions per flea), that of Nosopsyllus fasciatus to be 0·213 ± 0·157, and that of Orchopeas sexdentatus sexdentatus to be 0·170 ± 0·138. Opisodasys nesiotus, Megabothris abantis, Malaraeus telchinum and Diamanus montanus transmitted very inefficiently.

Experimental evidence was obtained that different strains of a species of flea may differ markedly in their biological vector capacity. In contrast to results obtained in this study, Wheeler & Douglas found Diamanus montanus to be an exceptionally good vector; in their studies it proved to be an even more efficient vector than Xenopsylla cheopis. The strain of Diamanus montanus employed by them came from an area widely separated from that in which the strain used in the present studies was originally collected.

Since many blocked fleas did not transmit it is probable that the experimentally determined vector efficiencies are lower than they would be in nature, where the blocked flea has constant access to a host and hence greater opportunity to feed.

Attempts to determine the number of organisms regurgitated by a blocked flea during its attempt to feed did not prove entirely satisfactory, but gave an indication that the number may be at times from 11,000 to 24,000 organisms. The technique consisted of feeding a blocked flea on the shaved abdomen of a mouse (later on the ear), then immediately doing a biopsy on the area around and including the bite wound. This biopsy material was then finely ground and plated on a sensitive bacteriological medium. Some mice upon which biopsies were performed nevertheless contracted plague and died. This must lead to the conclusion that an infective flea may deposit organisms directly into the capillaries and that the primary stage of infection resulting from a flea bite is frequently bacteraemia.
The feeding and breeding of laboratory animals. VI. The breeding of mice
Authors: Bruce H. M.
Published: May 2009

1. The total reproductive performance of two groups each of twenty-four mice over a period of one year under two different systems of mating has been recorded.

2. In the first system (monogamous pairs) the male was kept continuously with the female; in 78% of cases the females became pregnant again at post-partum oestrus and were thus subjected for the most part to unbroken intensive breeding.

3. In the second system (polygynous groups) several females were kept with one male and were removed to individual cages for the birth and rearing of the litters and were returned to the male again only after the litter had been weaned.

4. Under the first system 1149 young were successfully reared to weaning in one year by the twenty-four females; under the second system 559 young were weaned during the same period.

5. Mortality of breeding females, litter size, weight of young at weaning, the effect of parity, loss of litters and of young between birth and weaning and the sex-ratio of the young weaned were alike for both methods of mating.

6. The interaction of concurrent gestation and lactation upon the length of the gestation period is discussed, and regression lines showing the relation between the number of young suckled, the number of young in the uterus and the length of the gestation period are given.

My best thanks are due to Dr A. S. Parkes, F.R.S., for advice during the course of the work and for help in the preparation of the manuscript. I should also like to thank Dr C. W. Emmens for the statistical analyses and the calculation of the regression lines.
An antibiotic fromPfeifferella whitmori
Authors: Jameson J. E.
Published: May 2009

An antibiotic elaborated byPfeifferella whitmoriis described. This principle is activein vitroagainst the H37RV strain ofMycobacterium tuberculosis, but in several other respects closely resembles penicillin. It has given encouraging results in a small-scale therapeutic trial in experimental guinea-pig diphtheria.
A new antigenic relationship among faecal bacilli due to a common β antigen
Authors: Mushin Rose
Published: May 2009

1. The presence of a new thermolabile an named β antigen has been demonstrated in motile and non-motile coliform, paracolon andProteusstrains, and inShigellabacilli (Sh. flexneri Sh. flexneriV1 and D19). This antigen can be frequently found in the above types.

2. The characteristics of the β antigen have been described, and its dissimilarity to H, O, Vi, 2, A, B and α antigens has been established.

3. A high incidence of β antibodies was demonstrated in normal human and rabbit sera.

4. β strains of paracolon and coliform b injected intraperitoneally into mice were shown to be more virulent to mice than β minus forms of the same strains.

5. It is suggested that unrecognized presence of β antigen in cultures and β antibody in human and rabbit sera may cause errors in bacteriological and serological diagnoses of enteric infections.
Examination of floor dust for haemolytic streptococci
Authors: Williams R. E. O.
Published: May 2009

Floor dust has been collected for bacteriological examination by three methods: (1) with a miniature vacuum cleaner in which the ‘bag’ consists of a paper Soxhlet extraction thimable, (2)by sweeping, and (3)by blowing the dust on to the surface of a culture plate. The dust on to the surface of a culture plate. the dust from on to the first two methods was shaken with broth and an aliquot sample plated out on crystal-violet blood ager plates.

Surface inoculation of the plates was found to give somewhat higher counts than the use of pour plates, but otherwise minor variations in the routine were without great effect on the count.

Analysis of the results obtained in examining a number of specimerns from schoolrooms and day nurseries showed that, though the counts of streptococci in successive samples from one dust suspension agreed well, there was wide variation between the counts from duplicate samples of dust, however collected; the frequency distribution of the counts in rooms was of the log-normal type. It is clear that in routine work, all the dust collected from the whole floor of a room should be examined, in order to give the most reliable result.

Of 185 specimens in which four colonies of haemolyt streptococci were grouped, 67% had all four strains of group A. Ofniety-four samples in which four group A strains were typed, 55 % had all four strains of the same type; more than one type was found in 20 %.
Sodium fluoracetate (1080) as a rat poison
Authors: Barneet S. A. , Spencer Mary M.
Published: May 2009

1. Sodium fluoracetate (1080) has been tested in the field as a poison for Rattus norvegicus and R. rattus.

2. Direct poisoning (without Prebaiting) was used in thirteen tests on R. norvegicus. In eight of these tests censuses showed kills of at least 89% in three tests the poison failed, and in two the results were equivocal.

3. Of three similar tests against R. rattus two were successful and one was a failure.

4. Six tests of 1080 after prebaiting gave five successes (including one against R. rattus), and one in which the estimated kill was about 82%.

5. In five out of six tests populations of R. norvegicus which had survived baiting with 1080 showed shyness (refusal) of the poison when it was given in a new bait base.

6. The LD 50 of 1080 for a strain of white rats was found to be 3·8 mg./kg. (approx. range 2·8–5·2).

7. A number of wild brids and some domestic animals were accidentally killed during the tests despite stringent precautions taken in laying the bait and in warning occupiers.

8. It is concluded that: (a) although 1080 is probably more effective in direct poisoning than other poisons used in the past, it does not give as consistent results as the standard poisons do after prebaiting; (b) 1080 is too dangerous for general use.
The relationship between influenza and pneumonia
Authors: Stuart-Harris C. H. , Laird Joan , Tyrrell D. A. , Kelsall Margaret H. , Franks Zena C. , Pownall Margaret
Published: May 2009

1.The results are reported of a study cases of pneumonia, of upper respiratory indection and of family contacts of cases of pneumoia for evidence of influenza-virus infection between October 1947 and April 1949.

2. During an inter-epidemic period in relation to influenza, two sporadic cases of influenza-virus A infection were detected, one in a case of pneumo-coccal pneumonia and the other in a family contact of a case of pneumonia. These were the only instances of virus infection detected amoung 158 individuals including seventy-eight cases of pneumonia.

3. The epidemic of influenza from February to April 1949 was associated with an increase in number of notified cases of pneumonia, particularly in those over 45 years of age compared with the notifications in 1948. Deaths from pneumonia also increased, particularly in those of 65years or over.

4. During the period of influenza prevalence, direct tests of specimens in eggs and serological tests gave positive evidence of influenza prevalence, direct tests of specimens in eggs and serological tests gave positve evidence of influenza virus A infection in many instances. Twenty-six of forty-one cases of upper respiratory infection between February and April 1949 were positive for influenza A and one was a case of influenza B.

5. Eifgteen of fifty-five cases of pneumococcal and staphyococcal pneumoniaccal and staphylococcal pneumonia, eight of fifteen cases of bronchitis, one of two cases of bronchiectasis and four of six cases of congestive heart failure gave serological or cultural evidence of influenza virus A infection during the period of February to April 1949.

6. The mechanism of influenza-virus infection in relation to bacterial infection of the lower respiratory tract is discussed.
The persistence of dust in occupied rooms
Authors: Lowbury E. J.
Published: May 2009

Fluorescein dispersed as powder into the air of occupied rooms was extracted in measurable quantities from dust after as many as twenty previous sweepings.

The value of fluorescein in showing the rate of removal of dust from occupied environments is discussed in relation to the transfer of infection.
A preliminary study of the bacteriophages ofPseudomonas aeruginosa
Authors: Don Phyllis A. , van den Ende M.
Published: May 2009

Thirty strains ofPseudomonas aeruginosa, isolated from routine clinical material, were investigated, with particular reference to the metallic lytic effect and the bacteriophages they carry. From the filtrates of these strains, twenty-five bacteriophages or phage variants were isolated, and the effect of these on the various bacterial strains and some of their variants were investigated.

It has not been possible to elucidate the nature of the agent responsible for the metallic lytic effect. The true phages isolated, however, present many features of interest which warrant their more detailed study.

Part of this work was carried out in the Nkana Kitwe and C.S.I.R. virus research unit at the U.C.T. Pathology Department.
A study of the reaction of the white blood corpuscles in bovines at parturition with a consideration of the evidence of the action of the adrenal cortical hormone (cortisone)
Authors: Kerr W. R. , Robertson M. , McGirr J. L.
Published: May 2009

A study was made of the reaction of the white blood corpuscles in bovines at parturition.

Graphs made from the differential total counts of the white blood corpuscles from shortly before calving and at intervals through the period of parturition and for 24–48 hr. after calving show a definite absolute lymphopoenia with a rise in the neturophils.

The type of graph produced resembles that found in bovines when cortisone is injected.

The peak of the white blood cell reaction usually takes place about 5–9 hr. after the delivery of the calf. This is also the period of the peak reaction in the cellular relations after injection of cortisone.

The observations recorded seem to afford positive evidence that C 11 hydroxy steroids (cortisone) are poured out in the last stage of parturition in the normal bovine. The desensitization of the skin in animals which were sensitized to Trichomonas foetus an which was found at this time is considered to be connected with the action of the hormone.
The pathogenic and immunogenic activities ofSalmonella typhiin relation to its antigenic constituents
Authors: Felix A. , Pitt R. Margaret
Published: May 2009

1. The most virulent strains ofSalmonella typhiare those that develop both the Vi and O antigens in maximum quantities.

2. The Vi antigen is not a particularly toxic substance; it is less toxic for the mouse than the O antigen.

3. The main biological function of the Vi antigen is to protect the O antigen against the action of the natural or immune O antibody, thereby protecting the bacterial cell against phagocytosis and the bactericidal action of the serum.

4. The relative virulence for mice of freshly isolated strains ofSalmonella typhireflects their virulence for man.