bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Differentiation of the Staphylococci, with Special reference to the Precipitin Reactions
Authors: Dudgeon Leonard S. , Simpson J. W. Hope
Published: May 2009

(1) FiftyS. aureusand 30 S.albusstrains obtained from infective processes in man have been investigated. Such cultural reactions as were completed did not differentiate between strains of S. albus and S. aureus, or serve to group these cocci; we found, however, that 94 per cent, of the S. aureus strains fermented mannite, as opposed to 40 per cent, of the S. albus strains. These results are in accordance with the findings of Cummins and Cumming (1913) and Hine (1922).

(2) A close degree of correlation between pathogenicity for rabbits, pigment formation, and biochemical activity was noticed among theS. aureusstrains. Out of 19 pathogenic strains ofS. aureus, 9 showed medium pigmentation and 10 were strongly pigmented.

(3) Anti-sera were prepared by inoculating rabbits with living cultures, 24 hours old, of the various strains. TheS. aureusrabbits and a few of theS. albusreceived two preliminary doses of the specific vaccine, but little or no protective action was afforded from the doses of living cocci injected.

(4) Nineteen out of 25 cultures ofS. aureuskilled rabbits, but only 3 out of 18 cultures ofS. albus.

(5) Fifteen strains ofS. aureusand 15 ofS. albuswere used for the preparation of anti-sera, and tested against as many antigens as possible, by the methods described by Dudgeon and Bamforth.

(6) Cultures ofS. aureusproduced efficient anti-sera more readily thanS. albuscultures, but when an activeS. albusanti-serum was produced, it appeared to be as effective as theS. aureusanti-sera.

(7) A marked difference in efficiency betweenS. aureusandS. albusantigens was noted.S. aureusantigens were almost three times more active thanS. albusantigens.

(8) Pathogenic strains ofS. aureusandS. albusproduced more efficient precipitin antigens than non-pathogenic.

(9) From the microscopical examination of the deposit formed in the precipitin reactions, a difference was noted betweenS. aureusandS. albusantigens.

(10) The study of the precipitin reactions has failed to show any hard and fast dividing line between staphylococci of different colours, or of different cultural reactions. We are inclined to agree with Winslow, Rothberg and Parsons (1920) and with Dudgeon's original view in 1908, that the pyogenic, Gram-positive staphylococci must be regarded as members of one common family.
“Bacillus anthracoides.” A Study of its Biological Characters and Relationships and its Pathogenic Properties under Experimental Conditions
Authors: Grierson A. M. M.
Published: May 2009

1. There occurs in nature an organism belonging to the group of Gram-positive aerobic sporing bacilli which closely resembles B.anthracis, especially in its cultural characters.

2. These organisms occur commonly in materials that are frequently examined for the presence ofB. anthracis.

3. TheB. anthracoidesis pathogenic to guinea-pigs and mice under experimental conditions, and would appear to occupy a position between the virulentB. anthracisand the non-pathogenic members of the group of aerobic sporing bacilli, e.g.B. subtilis, B. mesentericus.

4. Subcutaneous injection of cultures ofB. anthracoidesproduces a local inflammation with gelatinous oedema and a fatal septicaemia.

5. Only large doses of living organisms are lethal and attempts to increase the virulence of this organism by various methods have not proved successful.

6. Individual animals vary considerably in their resistance to the organism.

7. With the exception ofB. anthracis, theB. anthracoidescontrasts with the other members of the group in its pathogenic properties under experimental conditions. Twenty-five strains of this organism have been isolated, each of which possesses pathogenic properties. The pathogenicity of 49 strains of other representatives of the group has been tested, and only one of these was found to have lethal effects.
Infra-red Radiation and Nasal Obstruction
Authors: van Dishoeck H. A. E.
Published: May 2009

For the investigation of the Hill phenomenon, viz. the antagonism of short-and long-wave infra-red radiation in their influence on nasal obstruction, the commonly used rhinomanometric technique is not well suited. In this paper a new procedure is described, in which an air current is blown through the nose. In this way the nasal passability may be estimated, independent of respiratory movements. It proved to be desirable to make a selection of suitable experimental subjects with the aid of adrenaline and histamine tests; only those persons in which the opening by adrenaline and the narrowing by histamine sprays were clearly demonstrable were chosen.

Long-wave infra-red rays constantly caused nasal obstruction.

The shorter waves were much weaker in their shutting effect, and also decreased the narrowing of the nose when they were given in combination with the long-wave rays of an electric fire.

A nasal passage closed by long-wave infra-red radiation may be partly opened by the short-wave rays; the possibility of surface cooling being the opening factor was excluded.

Artificial cooling of the skin has a very marked opening influence.

It is suggested that nose-opening and nose-shutting are correlated with cooling and heating of the Malpighian layer. Long infra-red rays will be completely absorbed in the layer and cause capillary stasis with local overheating. The shorter waves for the greater part penetrate more deeply; the skin reacts by an active hyperaemia, which, by relatively cooling the overheated Malpighian layer, has the same effect as a cooling from without.
Carriers and Return Cases in Scarlet Fever
Authors: Brown W. A. , Allison V. D.
Published: May 2009

1. In view of the high carrier rate on discharge from hospital, the bacteriological examination of swabs from scarlet fever patients is of no value in the detection of probable infecting cases.

2. There is, however, a definite relationship between the degree of infection, as measured by the profusion of haemolytic streptococci in cultures on discharge, and the likelihood of the patient infecting others.

3. The causal connection between “infecting” case and return case is strongly supported by finding the same serological type ofStreptococcus pyogenesin both cases.

4. A patient who has had complications in hospital is slightly more liable to become an infecting case than one whose course has been uncomplicated.

5. The commonest age group of infecting cases is 5–10 years.

6. The majority (70 per cent.) of the return cases occurred within 14 days of the arrival home of the infecting case.

7. Overcrowding in the home, and the number of the susceptibles exposed do not appear to be important factors in the production of return cases.

8. A history of tonsillectomy does not appear to bear any important relationship to the occurrence of infecting cases, but the inconclusive nature of our findings indicates the desirability of further investigation of this question and that of the relation of the condition of the tonsils to their infectivity.

9. Discharge from hospital as early as is consistent with a satisfactory clinical condition is shown to be advantageous from the point of view both of the patient and of the hospital administration.

10. The administration of scarlatinal antitoxin is likely to render a patient less liable to convey infection on discharge.
Skin Temperature in Relation to the Warmth of the Environment
Authors: Bedford T.
Published: May 2009

The skin temperatures of industrial workers, mainly women and girls, engaged in very light occupations, have been correlated with environmental conditions. The temperatures of the forehead and of the palm of the hand were measured with a Moll radiation thermopile, and for the temperature of the foot a thermo-junction was used. Altogether 3085 sets of observations were made.

Various measures of environmental warmth (dry-bulb air temperature, equivalent temperature, effective temperature, and dry kata cooling power) were correlated with skin temperature. The dry-bulb air temperature is about as good an index of skin temperature as any of the other measures used, while it appears that skin temperature may be slightly less closely associated with dry kata cooling power than with the other measures of warmth conditions.

At an average air temperature of 18° C., the average skin temperatures observed were: on the forehead 34·25° C.; on the palm of the hand 29·2° C.; and on the foot 24·4° C. The average increases in skin temperature for a rise of 1° in air temperature were: on the forehead 0·139°; on the hand 0·465°; and on the foot 0·806° C.

There was much variation in the skin temperatures recorded at any particular air temperature. The root-mean-square errors of estimation of skin temperature from air temperature were 0·81, 2·51, and 2·80° C., for the forehead, hands and feet respectively.

Correlations between the temperatures of different areas of skin were rather lower than those between air and skin temperature.
Is Cancer Mortality Increasing or Decreasing?
Authors: Wolff George
Published: May 2009

We have heard much in recent times of the decrease of tuberculosis and of the increase in mortality from cancer. I propose on the basis of data from some great cities and other areas of the German-speaking world to ascertain whether, if attention is paid to age distribution, cancer really presents so striking a contrast with other causes of mortality. With a view to solving the problem let us enquire whether the undoubted absolute increase may not be a mere function of the ageing of the population, a feature common to all civilised countries. Most weight will be placed upon the statistical data derived from cities because of the greater reliability of the diagnoses in hospitals, and because, as a rule, the death certificate is filled up by the practitioner who actually attended the patient.
The Occurrence of Typhoid Bacilli Containing Vi Antigen in Cases of Typhoid Fever and of Vi Antibody in their Sera
Authors: Felix A. , Krikorian K. S. , Reitler R.
Published: May 2009

The investigation recorded in the present paper was undertaken as a corollary to the clinical trials with a new antityphoid serum, the results of which were recently published (Felix, 1935). Its object was to enquire into:

(i) the occurrence of Vi antigen in strains of B. typhosus freshly isolated from cases of typhoid fever;

(ii) the occurrence of Vi antibody in the blood serum of typhoid patients and convalescents.
On the Cultivation of the Nitroso-Bacterium
Authors: Fremlin H. S.
Published: May 2009

In the first place cultures of the nitroso-bacterium were developed in inorganic solutions. These carried to a 5th dilution exhibited practically a pure culture of this species.

Secondly, cultures of the nitroso-bacterium were inoculated into solutions containing small quantities of organic matter. In these they were able to oxidise the ammonia present. It was found that a culture developing in the presence of small quantities of organic matter was better able to oxidise the ammonia in higher percentages of organic matter than a culture taken directly from an inorganic solution.

In growing this species on plates silica jelly has the disadvantage of being difficult to prepare. It was 18 months before I obtained a satisfactory plate. This jelly grows the nitroso-bacterium well, but other species can also develop colonies on it. Ammonia agar also grows the species, as shown by the oxidation of the ammonia, and the colonies assume a characteristic form.

As to beef broth agar and gelatine, these media grew colonies of a micro-organism similiar to the nitroso-bacterium from oxidised ammonia cultures. Pieces of these plates containing such colonies in pure culture frequently oxidised ammonia in solutions. On the other hand pieces of such plates showing no colonies never produced any oxidations of the ammonia. Furthermore the single colonies from silica and ammonia agar plates, which oxidised the ammonia in the media into which they were sub-cultured, grew well on beef broth agar and gelatine.

From the above results I have come to the following conclusions:

(1) That the nitroso-bacterium grows well on any ordinary medium.

(2) That the supposed parallel organism is no other than the nitroso-bacterium itself.

(3) That in the presence of large percentages of organic matter the nitroso-bacterium, although growing very profusely, loses for a time the power of converting ammonia into a nitrite.
Birth-Rate and Death-Rate in New Zealand
Authors: Barclay W. J.
Published: May 2009

Of all British colonies New Zealand is the one that most closely resembles Great Britain in size, in situation, and in climate. And the inhabitants of the two countries are of practically the same race. The vital statistics of New Zealand are therefore eminently suitable for comparison with those of Great Britain. In the present paper comparison has been restricted to the birth-rates and death-rates, and in this limited survey several points of interest present themselves.
XII. The pathological histology of the spleen and liver in spontaneous rat-plague, with observations on the experimental infection
Authors: Ledingham J. C. G.
Published: May 2009

The pathological histology of plague in man and experimental plague in animals has already been the subject of several researches, notably those of Aoyama (1896), Yamagiwa (1897), Albrecht and Gohn (1897), Dürck (1904) and Hamdi (1904) in the case of human plague, and of van der Stricht (1897), Honl (1897), Lustig and Zardo (1897), Babes and Livadite (1897), Albrecht and Gohn (1900) and Sata (1900) in the case of experimental plague.
Experimental Studies Relating to Ship-beri-beri and Scurvy. II. On the Etiology of Scurvy
Authors: Holst Axel , Frölich Theodor
Published: May 2009

(1) On the macroscopical alterations in the tissues of guinea-pigs which had been fed exclusively on bread, groats, and unpeeled grain.

By experimenting with the “one-sided” diets which were used in the experiments, mentioned in the foregoing paper on polyneuritis in poultry, we found that guinea-pigs also contract a disease, and that this disease is accompanied by very characteristic changes.
On the Nature of the Cellular Elements Present in Milk. Part II. Quantitative and Qualitative Results
Authors: Hewlett R. Tanner , Villar Sidney , Revis Cecil
Published: May 2009

In a preliminary report (Hewlett, Villar and Revis, 1909, p. 278) published last year a summary of conclusions at which we had arrived with regard to the nature of the cellular elements present in milk was set forth. These conclusions were formulated on results obtained during a prolonged quantitative and qualitative examination of these cellular elements in milks obtained from known sources under veterinary supervision, and possess, we believe, a chronological significance which, with the exception of results published by Russell and Hoffmann (1907), has been somewhat lacking in many investigations. For this purpose we selected four dairy farms at which milk was being produced for sale on ordinary commercial lines, but under various conditions of environment, both architectural and sanitary. Together with these we were also enabled, through the kindness of Professor Percival, to make use of cows in the experimental herd of the University College of Reading.
The Contamination of Ice-cream
Authors: Buchan George F.
Published: May 2009

(1) The premises of 50 manufacturers of ice-cream were inspected, their methods investigated, and bacteriological examinations made of samples taken

“a” immediately after heating,

“b” after cooling,

“c” after freezing.

(2) The trade is not carried on under the conditions or with the precautions necessary to secure a clean product.

The sources of the contamination of ice-cream.

(3) Bacteriologically polluted ice-cream is due to

(A) Insufficient initial heating;

(B) Contamination during cooling and freezing from

(a) unclean vessels and covers,

(b) the addition of unclean ice to hasten freezing,

(c) the unclean hands of the manufacturer,

(d) dirty surroundings.

The scientific method of the manufacture of ice-cream.

(4) To secure a pure ice-cream:

(a) All vessels should be thoroughly cleansed immediately before use and reserved for the manufacture of ice-cream. They should be stored in a clean place.

(b) The manufacturer's hands and forearms should be thoroughly scrubbed and cleansed before each stage of the process. The clothing likely to come in contact with the ice-cream should also be clean.

(c) Fresh milk should be used in its manufacture.

(d) The ingredients should be boiled directly over a fire for ten minutes, or heated by means of a water-bath at boiling point for 30 minutes. The latter method is the better as the former is liable to burn the mixture.

(e) The mixture should be frozen, immediately after boiling preferably in a freezer of the American pattern. Thereafter the ice-cream should be kept frozen while in the vendor's possession.

(f) No ice-cream should be exposed for sale 48 hours after boiling.

(g) The premises on which ice-cream is manufactured should be approved and registered by the local authority and should be constantly supervised.
The Sterilization of Empty Milk Churns by Steam under Pressure
Authors: Mattick A. T. R.
Published: May 2009

In a previous paper it was shown that of the empty milk churns which were examined, 56 per cent, were totally unfit for use, as they contained very large numbers of bacteria and lactose fermenting organisms in high proportion. Table I (1) is taken from this paper and gives the number of bacteria per 1 c.c. of washings with sterile saline solution. These churns were taken at random on a station platform, their origin being unknown.
A New Method of obtaining Cultures from Single Bacterial Cells
Authors: Topley W. W. C. , Barnard J. E. , Wilson G. S.
Published: May 2009

While investigating variations in agglutinability, occurring among certain strains of paratyphoid bacilli, it became desirable to obtain cultures derived from single bacterial cells. The technique at first adopted was that devised by Mutch (1919), but the results obtained were not satisfactory. Certain modifications of this method were attempted, but were no more successful.

The main difficulty, and one which appears to us to have been far too little emphasised in all the methods hitherto described, has been encountered in obtaining satisfactory conditions for the microscopical observation of the bacillary suspensions employed. The difficulty of accurately observing hanging-drop preparations, and still more of controlling manipulation of them by microscopical observation, would seem to us to have been insufficiently realised; and the ease with which faulty interpretation of microscopical appearances may introduce fatal errors into work of this kind has not, perhaps, been fully taken into account.
Certified Milk in Relation to the Bacteriological Standard
Authors: Mattick A. T. R. , Williams R. Stenhouse
Published: May 2009

This paper contains an analysis of the results of the bacteriological examinations of 184 samples of milk produced by Mr W. G. Symes, Manor Farm, Fordington, Dorset, between April 1st, 1921 and June 6th, 1924.

The farmer holds a licence to produce Certified Milk which is despatched from the farm in sealed glass bottles. The samples were taken at random from the milk as it was bottled and were at once despatched by post to the laboratory, without placing in cold store. The age of the samples varied from 20–24 hours at the time of examination.
On Staphylococcal Precipitin Reactions in Cases of Acute and Chronic Infections and also in Serum Sickness
Authors: Dudgeon Leonard S. , Bamforth Joseph
Published: May 2009

This work was undertaken for the purpose of determining the occurrence and specificity of bacterial precipitins in infections caused by the Staphylococcus aureus. The differences in antigenic properties of various strains of orange and white staphylococci employed in the preparation of the filtered antigens and the importance of the presence of peptone in this connection led to numerous experimental observations which had not been anticipated. The presence of strong S. aureus precipitins in the blood of an adult suffering from very acute serum sickness following an injection of anti-diphtheritic serum led to an investigation of the blood of patients suffering from serum sickness, the results of which are fully recorded here. The investigation of the blood of normal rabbits revealed the fact that in some of these animals staphylococcal precipitins were present, which led to unexpected difficulties in the study of precipitins in the actively immunised animal.
Weight, Height and Nutrition: Observations from the Isle of Ely
Authors: Lonie Thomas C.
Published: May 2009

The Isle of Ely is the northern half of the geographical County of Cambridge-shire and forms in itself a separate administrative county. It is the heart of the fen country, and its population is one which long retained a degree of isolation and independence tending to preserve in its members certain mental, and perhaps physical characters peculiar to themselves. It is interesting to recall that from this neighbourhood came Boadicea, Queen of the Iceni, and Hereward the Wake, who proved such stubborn enemies to the conquerors of their country.
The Incidence of Intrathoracic Tumours in Leeds
Authors: Bonser Georgiana M.
Published: May 2009

In 1928–9 was published the result of an investigation into the incidence of tumours of the respiratory tract based on an analysis of the post-mortem records of the General Infirmary at Leeds between the years 1891 and 1927 inclusive. It was shown that there had been no increase in intrathoracic cancer at post-mortem during this period, that the incidence was not as high in Leeds as it was in Manchester and that the disease affected men more commonly than women in the proportion of 3½: 1. It was also shown that there was a general tendency towards an increase in lung cancer in post-mortem statistics of other hospitals, especially in Germany.
Filtration Experiments with Spirochaeta Schaudinnii
Authors: Smith E. C.
Published: May 2009

It has been shown that S. schaudinnii will easily pass through Berkefeld V filters under a negative pressure of considerably less than one atmosphere, but B. pyocyaneus was always found in the filtrates in association with the spiro-chaetes. Attempts to pass S. schaudinnii through Berkefeld N filters were uniformly negative.

Inoculation experiments on native volunteers made with (a) filtrates containing S. schaudinnii and B. pyocyaneus, (b) a mixture of these organisms combined with B.fusiformis, and (c) an emulsion of B.fusiformis in broth, did not give rise to ulceration.
Oxygen and carbon dioxide subcutaneous tissue gas tensions in cases of hypertension
Authors: Ellman Philip , Taylor H. J.
Published: May 2009

From results obtained from the twenty-two patients with essential hypertensions we find that their CO2 and O2 subcutaneous tissue gas tensions lie within normal limits. Thus (1) there can be no thickening of the capillary walls, and (2) the blood flow through the capillaries is normal.
The spermicidal powers of chemical contraceptives VII. Approved tests
Authors: Baker John R. , Ranson R. M. , Tynen J.
Published: May 2009

1. All tests of spermicidal power are done with human semen at 37° C.

2. The total spermicidal power of pure substances and commercial products is measured by a test which is not intended to represent natural conditions very closely, but which gives consistently reliable results. The activity of the sperms is determined at 5 and at 30 min.

3. A commercial product of high total spermicidal power may be useless on account of the slow rate of diffusion of the spermicide out of the vehicle. A special test measures the rate of diffusion. This test is designed to represent natural conditions as well as is possible in the laboratory. The test is made as stringent as possible by avoiding mechanical mixture of the product with the semen. The activity of the sperms is determined at 2, 5, 15, 30, 60, 120, and 180 min.

4. The rate of disintegration and acidity or alkalinity of commercial products is measured.

5. The pathological test consists in inserting one-half the prescribed dose of a commercial product into the vagina of a bitch daily (except Sundays) for a fortnight, and then sectioning the vagina and examining microscopically.

6. A method is described whereby the pH of human semen may be determined colorimetrically rather accurately.

7. The average ejaculate of the human semen we have studied, from 13 donors, measures 3·9 c.c, contains 461 million sperms, and requires 3·1 c.c. of N/100 HCl to neutralize it.
Notes on the Subject Matter of a Previous Paper
Authors: Buchanan-Wollaston H. J.
Published: May 2009

The meaning of the footnote on p. 162 is somewhat ambiguous and the statement comprised in it is not true for all values of n, the number of differences in N.F.T. of which the significance of the mean is tested.

The statement that, by the use of a certain approximate distribution, significance of an observation is underestimated means that the estimated value of P in the neighbourhood of the significance level is greater than the true value.
A Modification of Wilson and Blair's Bismuth Sulphite Agar (Stabilized Stock Solutions)
Authors: de Loureiro J. A.
Published: May 2009

Bismuth sulphite agar is by far the most efficient of all single media devised for the isolation of typhoid bacilli from stools. When tested in comparison with other media it was found not only to afford the highest percentage of positive results but also the maximum inhibition of saprophytic growth. Its remarkable selectivity is demonstrated by the fact that negative plates are often completely sterile, and positive ones often consist exclusively of typhoid colonies (Loureiro & Matos, unpublished observations).
An investigation of the merits of ozone as an aerial disinfectant
Authors: Elford William J. , van den Ende Joan
Published: May 2009

The question formulated in the introduction to this report can now be answered. Ozone in tolerable concentration is able to inactivate certain bacteria when these are present as unprotected singleton aerosol particles in atmospheres of 60–90% R.h. When such bacteria are covered with a protective coating of organic matter, however, as in aerosols naturally emitted during a sneeze or cough, then ozone in permissible concentration is without significant effect. Inactivation of such protected organisms can only be achieved by the use of ozone in decidedly higher concentrations, which must be deemed dangerous for prolonged spells of breathing. Bacteria that have settled on surfaces are generally more resistant to ozone than when in newly formed aerosols. Hence experimental evidence leads to the conclusion that ozone, in concentrations that can be breathed over long periods without irritation, cannot be expected to provide any effective protection against air-borne bacterial infection, through direct inactivation of the infectious carrier particles.
The Lipoid Antigens of C. Diphtheriae and C. Hofmannii
Authors: Hoyle L.
Published: May 2009

1. Antisera prepared by immunizing rabbits with C. diphtheriae gravis, mitis, and intermedius and C. hofmannii contain antibodies which will give complement-fixation reactions with alcoholic extracts of the organisms.

2. By means of cross-absorption experiments three different lipoid antigens can be demonstrated: (a) a specific antigen h present only in C. hofmannii; (b) a specific antigen d characteristic of C. diphtheriae mitis but probably present also in small amount in C. diphtheriae gravis and intermedius; and (c) a non-specific or group antigen G present in large amount in C. diphtheriae gravis and intermedius and C. hofmannii, and in small amount in C. diphtheriae mitis; this G antigen is probably made up of a number of components.

3. Sera of human diphtheria convalescents may contain antibodies reacting with alcoholic extracts of C. diphtheriae. Sera from mitis cases usually react only with extracts of G. diphtheriae mitis, i.e. they contain only d antibody, while sera from gravis or intermedius cases usually contain only G antibody and react with extracts of C. diphtheriae gravis, intermedius and C. hofmannii, but not with extracts of G. diphtheriae mitis.
Bacteriological observations on the air of occupied premises: I. air disinfection with hypochlorites. a simple practical method of disinfecting the air of occupied premises
Authors: Challinor S. W.
Published: May 2009

Substantial reduction in the bacterial content of the air of an empty room after infection with B. prodigiosus (or with Staphylococcus albus or a diphtheroid bacillus) has been effected by means of hypochlorites introduced into the air by atomization from a Dynalysor or by spraying from a flit gun.

The ‘normal’ variation of the bacterial content of the air of an occupied (crowded) room has been described.

Repeated spraying of a solution containing 1% of sodium hypochlorite or of a 1·3% suspension of water-sterilizing powder (bleaching powder) from a flit gun has been shown to reduce materially the bacterial content of the air of the occupied room.

Similar sprayings of water have been shown to have no appreciable effect on the bacterial content of the air of the occupied room and the action of the hypochlorite was, therefore, not merely a mechanical removal of bacteria from the air.

Methods have been devised for assessing the degree of disinfection per individual spraying of hypochlorite, and, although the methods are mainly of comparative value, it may be stated that the reduction in the total bacterial content of the air of the occupied room for a single spraying of hypochlorite Y (≡1% sodium hypochlorite) was of the order of 33%, or more. The percentage reduction of potentially pathogenic bacteria which may have been present was almost certainly greater than the reduction of the total bacterial content, which included resistant saprophytic bacteria. The average concentration of hypochlorite Y used in these experiments was 0·38 c.c. per million c.c. of air (i.e. less than 11·0 c.c. per 1000 cu. ft. of air) per spraying, i.e. was exceedingly small, and even smaller concentrations were equally effective when the hypochlorite was atomized into the air by means of the Dynalysor.

Rather less consistent results were obtained with the chemically less active bleaching powder suspension than with hypochlorite Y in the flit-gun experiments.

The relative humidity of the air has been shown to be a factor of great importance, and in the experiments described in this paper effective air disinfection was not obtained at low relative humidities at temperatures ranging from 54 to 74° F. The need for accurate determination of the critical lower limit of relative humidity is stressed.

Tobacco smoke has been shown to reduce the efficiency of hypochlorite sprays but the experimental evidence was insufficient for any definite conclusion to be drawn.

The advantages and disadvantages of hypochlorites as air disinfectants have been discussed and the conclusion reached that repeated (every 20 or 30 min.) spraying of the air of an occupied room with a 1% solution of hypochlorite (e.g. hypochlorite Y) constitutes a simple, practical, inexpensive and efficient method of air disinfection, and, provided simple precautions are observed, there are no serious objections to such a procedure.
The effect of temperature of incubation on the results of tests for differentiating species of coliform bacteria
Authors: Taylor C. B.
Published: May 2009

1. A study has been made of different types of coliform bacteria with particular reference to (a) their ability to ferment lactose in MacConkey broth at different temperatures, and (b) the effect of using different temperatures of incubation for the indol, methyl-red, V.P., and citrate tests.

2. It was found that 97% of the cultures ofBact. coli(indol positive, methyl-red positive, V.P. negative, citrate negative) examined could ferment lactose with production of acid and gas between 40 and 44° C. The number was not appreciably reduced at 45° C. but was markedly reduced at 46° C. 28% of the cultures ofBact. coli(indol negative, methyl-red positive, V.P. negative, citrate negative) and 15% ofBact. aerogenes(indol negative, methyl-red negative, V.P. positive, citrate positive) were found to be positive at 44° C.

3. The adoption of a temperature of incubation of 30°C. for the V.P. test as advocated by Levine (1941) and the use of O'Meara's test showed that many cultures previously regarded as unable to produce acetylmethylcarbinol were in fact able to do so. Employing a temperature of 30°C. for 5, or in some cases 7, days for the methyl-red test, it was found that with nearly all the cultures tested there was an inverse correlation between the results of the methyl-red test and those of the V.P. test. With these modifications in technique some cultures originally designated as Intermediate type I were found to have reactions corresponding with those ofBact. aerogenestype I. Similarly, many cultures originally classified as Intermediate type II should have been typed asBact. aerogenestype II.

4. It was found that all cultures of Intermediate type I classified as such by the new technique were incapable of using the nitrogen of uric acid for growth, but that the majority produced hydrogen sulphide. Cultures ofBact. aerogenestype II, on the other hand, grew well in uric acid medium, but produced no hydrogen sulphide.

The investigation described in this paper was carried out by the Freshwater Biological Association, as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research. The paper is published by permission of the Department.
Further work on forecasting smallpox epidemics in India and British tropical countries based on previous climatic data
Authors: Rogers Leonard
Published: May 2009

1. Earlier work on forecasting epidemics of smallpox in India, based on the study of the previous rainfall and humidity, has been confirmed and extended by the present study and a few instances which did not conform to the general rule have been explained as due to the spread of the disease from an adjacent province.

2. An extension of the inquiry to other tropical countries of the British Empire indicates that in tropical countries in general with well-marked dry and wet seasons, the annual decline of smallpox incidence to a low minimum in relation to high absolute humidities during the rainy season is the rule; for it is absent in equatorial Uganda with rains throughout the year, and both the monsoon period and the monthly incidence of smallpox are reversed in such a Southern Hemisphere country as Nyassaland in accordance with the general rule.

3. Where smallpox is endemic in such countries increased prevalence in any year may usually be foreseen by watching the meteorological records in time to control the expected increase to some extent by increased use of vaccination.

4. Other air-borne diseases are worthy of study on similar lines in countries with suitable vital statistics and climatic conditions.
Nuclear reorganization in non-sporing bacteria
Authors: Bisset K. A.
Published: May 2009

1. The process of nuclear fusion and reorganization as it occurs in members of the Bacteriaceae is described.

2. The chromosomes behave as pairs at all times, the normal bacillus, of smooth morphology, contains two pairs.

3. The fusion nucleus contains three pairs and is preceded by a corresponding trinucleate bacillus.

4. One division of the chromosomes takes place in the fusion nucleus, and another during the process of redistribution of the chromosomes. The second division is followed by fragmentation, and return to the bacillary condition.
Agglutination of red blood cells of different animal species by influenza and Newcastle disease viruses
Authors: Chu C. M.
Published: May 2009

The agglutination of red cells of seventeen animal species by influenza and Newcastle disease viruses has been quantitatively investigated. The peculiar behaviour of one group of red cells, illustrated by ox, toward influenza virus heated for 30 min. at 56° C. and toward purified N.D.V. has been studied in detail. It is concluded that heated influenza virus acquires an apparently increased titre against ox cells because it has lost its eluting power. Similarly, purified N.D.V. is less readily eluted from red cells, due to the elimination of an ‘elution-hastening factor’ present in infected fluid. The present study illustrates the importance of careful adjustment of all possible variable conditions for individual viruses and individual red cell systems.
The counting of surface colonies of bacteria
Authors: Crone P. B.
Published: May 2009

A colony count performed by spreading a known volume of suspension on the surface of a plate possesses certain advantages over other methods, of which the chief is ease of counting.

The distribution of counts of several samples of the same suspension on medium of the same age and batch is as expected on statistical grounds.

Different batches and ages of blood plates may give substantially the same count but this is not true for Leifson's and Wilson & Blair's media.

A diluting fluid, which is satisfactory if blood agar is the plating medium, may not necessarily be so if special media are to be used.
The effects of air temperature and velocity and of various flooring materials on the thermal sensations and skin temperature of the feet
Authors: Munro A. F. , Chrenko F. A.
Published: May 2009

When complaints of cold feet are made in rooms with concrete floors, there is a tendency amongst people to attribute the discomfort directly to the concrete. It is, of course, obvious that to a bare foot concrete feels very much colder than a cork or wood surface; but it is not so apparent how a floor of comparatively high thermal conductivity such as concrete can appreciably affect the feelings of warmth when the feet are shod. Even the light footwear usually worn by women, being composed of more than one layer of material, must offer considerable resistance to heat loss. In addition, the area of the sole of the shoe in actual contact with the floor is small.
Toxoplasma infection at different ages, studied by the skin-test method
Authors: Hedqvist T.
Published: May 2009

On the basis of previously published work, the skin test for toxoplasmosis has been judged to be a convenient and sufficiently reliable method for carrying out epidemiological group investigations intended to elucidate the spread of the disease. With it one can probably detect as many persons with serologically demonstrable antibodies against toxoplasma as when the same persons are examined by means of the routine dye test. An investigation employing skin testing has been carried out on 648 persons between the age of 0 and 45 years, all living in or adjacent to a town in Central Sweden. The reagent used (toxoplasmin) was prepared from toxoplasma cultures grown on embryonated hen's eggs by the State Bacteriological Laboratories, Stockholm. Amongst 379 children under the age of 15 years, only one gave a positive reaction, whereas in the higher age groups the frequency of positives rose rather rapidly to 40% in the age group 30–45 years. The results show fair agreement with those previously reported from similar investigations, with one very noticeable exception: in North Sweden skin reactions have proved positive in a bare 10% of adults studied. The significance of this observation is discussed in regard to the epidemiological characters of the disease. Having due regard to our incomplete knowledge of the subject, attention is drawn to the possibility that reservoirs of infection are extrahuman and that transfer of the disease to human beings occurs through the medium of biting insects or contaminated food.
The conglutination phenomenon IX. The production of immuno-conglutinin in rabbits
Authors: Coombs A. M. , Coombs R. R. A.
Published: May 2009

1. An investigation has been carried out into the conditions necessary for the production of immuno-conglutinin in rabbits.

2. The inoculation of complement adsorbed on sensitized cells stimulates the production of immuno-conglutinin. We have called this procedure hetero-stimulation.

3. Immuno-conglutinin also results from the inoculation of untreated but killed bacteria. This procedure for its production we call auto-stimulation. Gram-negative bacteria appear to be more effective stimulants than Gram-positive bacteria. Soluble antigens did not appear to be as effective as bacterial suspensions.

4. The necessity for clarifying the part played by immuno-conglutinin in in vivo immune processes has been stressed.

The authors would like to thank the following for gifts of experimental materials: Mr H. I. Field, strains of S. pullorum; Dr J. Boissard, strain of C. hofmanni; Dr C. H. Lea and Dr R. S. Hannan, purified casein; Miss Dunkerley, Bence Jones protein. Cx polysaccharide for testing acute phase protein in rabbit serum was made available by the kindness of Dr McCarty of the Hospital of the Rockefeller Institute for Medical Research, New York; and much of the work on this aspect was done in consultation with Dr H. C. Anderson, to whom we are most grateful.
The effect of sodium thiosulphate on the coliform and Bacterium coli counts of non-chlorinated water samples
Authors:   By the Public Health Laboratory Service Water Sub-Committee
Published: May 2009

A quantity of 0.1 ml. of a 3% solution of crystalline sodium thiosulphate in a 6 oz. bottle is sufficient to neutralize up to 5 p.p.m. of residual chlorine; the use of large quantities of thiosulphate is unnecessary, except possibly for some swimming-bath samples. The investigation has shown that this amount of thiosulphate has no significant effect on the coliform or faecal coli content of non-chlorinated water samples during 6 hr. storage at refrigerator temperature. There therefore appears to be no disadvantage in adding this amount of thiosulphate to all water sampling bottles.
The dilution assay of viruses. II
Authors: Moran P. A. P.
Published: May 2009

If A is the average density of virus particles per unit volume and am(a)l, m= 2, 1,0, 1,2,) are the dilution levels, the proportion of eggs remaining sterile at dilution am (if eggs are used as the material to be infected) will be e~Xam if the ordinary assumptions of dilution assay are valid. In many cases this is not true because the eggs vary amongst themselves in their infectibility. If p is the probability of any one particle (when present) being infective for an individual egg, and if p does not vary from particle to particle the probability of the egg remaining sterile is e~pXam. If p varies from egg to egg so that it has a probability distribution/(p), the probability of an egg chosen at random remaining sterile is
Murray Valley encephalitis and Australian X disease
Authors: Anderson S. G.
Published: May 2009

Of the outbreaks of severe human encephalitis which have been recorded in Australia, five conformed to one clinical and epidemiological type. The disease was designated Australian X disease in 1917, 1918, 1922 and 1925 and Murray Valley encephalitis (MVE) in 1951. The causal virus was transmitted to laboratory animals during 1917, 1918 and 1925, but was not retained for later comparison with other viruses. The virus was isolated again during 1951 and identified as a new member of the arthropod-borne encephalitides, closely related to, but distinct from, Japanese B encephalitis virus.
The use of influenza virus labelled with radio-sulpher in studies of the early stages of the interaction of virus with the host cell
Authors: Hoyle L. , Finter N. B.
Published: May 2009

1. Influenza virus can be labelled with 35S by cultivation in fertile eggs into which radioactive methionine has been introduced.

2. When virus labelled with 35S is fractionated by ether treatment the nucleoprotein soluble antigen fraction contains 15 % of the 35S, the haemagglutinin also contains 15%, while the denatured envelope protein contains 70% of the 35S.

3. When sulphur-labelled virus is introduced as a primary inoculum in fertile eggs and extracts of the chorioallantoic membrane are made 1–20 % of 35S is recovered as amino-acid, while the remainder is present as non-infective material of particle size similar to that of the original virus.

4. It is suggested that on entry into the cell the virus nucleoprotein is hydrolysed with the release of amino-acid and free nucleic acid, while the virus envelope protein and haemagglutinin remain on the cell surface.

The authors are indebted to the Medical Research Council for a grant in aid of expenses, and to Messrs. Eli Lilly and Co. for the generous provision of the Spinco centrifuge used in this work. The radioactive methionine was obtained from the Radiochemical centre at Amersham.
The Use of Tests on Slaughterhouse Cattle for Estimating Relative Potencies of Tuberculins and for the Calculation of Discrimination Tests
Authors: Paterson A. B. , Stuart P. , Lesslie I. W. , Leech F. B.
Published: May 2009

1. The potency of PPD tuberculin made from AN 5, a bovine strain, was high when WR medium was used and low when BAI medium was used. PPD tuberculin made from strains of the human type grown on BAI medium was intermediate in potency between the two bovine PPDs.

2. The standard deviation of the difference between responses to duplicate injections of human type PPD at 2·0 mg./ml. concentration was 2·59 in the Islington and 1·84 in the Weybridge experiment on tuberculous animals, and 1·11 at Islington and 1·13 at Weybridge on tubercle-free animals. Differences greater than 1·5 mm. were relatively infrequent on tubercle-free animals.

3. The Elliott ‘401’ electronic computer at Rothamsted was used to calculate discriminant functions and to estimate the discriminating power of different ‘tests’, each test involving an injection of a mammalian and an injection of avian tuberculin.

4. There were some differences between the mammalian preparations in their power to discriminate between tuberculous and tubercle-free animals, but these differences were closely allied to differences in potency. It seems probable that if concentrations of equivalent potency were used, there would be little if any difference in their discriminating power.

5. The contribution of avian tuberculin to the discrimination test was demonstrated; the greatest contribution came from a concentration of 0·25 mg./ml. used in the Islington experiment. The Weybridge results were quite consistent with the assumption that a maximum contribution is made by a concentration less than 0·5 mg./ml.

6. Methods for deducing rules for the interpretation of comparative tuberculin tests, using a mammalian and an avian tuberculin are illustrated and results given for the type of population sampled in these experiments.

7. The principle on which this rule might be modified where the population is believed to be free of infection, is outlined and discussed.

We should like to acknowledge the advice and constructive criticisms during the planning of the experiments of Dr A. W. Stableforth and Dr H. H. Green of Weybridge, and also the care with which Miss C. N. Hebert carried out the preliminary arrangement of the large quantity of data. Thanks are also due to the staff of the Islington abattoir for their willing co-operation.