NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
J. K. MAKHIJANI AND B. N. BANERJEE
25
TABLE IV
Carotene content in blood in mg. per c.c.
Date
8th Sept. 1936
16th Sept. 1936
22nd Sept. 1936
26th Sept. 1936
1st Oct.
1936
6th Oct. 1936
Group A
Cow Nos.
256
0.00027
0.0004
0.00055
0.00088
0.0022
0.00216
257
0.000245
0.00041
0.00076
0.00091
0.00180
0.00184
Group B
Cow Nos.
247
..
0.00035
..
0.00068
0.00117
0.00109
263
..
0.00048
..
0.00053
0.00124
0.00121
Group C
Cow Nos.
274
..
0.00032
..
0.000565
0.00126
0.00114
278
..
0.00046
0.00048
0.00064
0.00103
..
Carotene in ghee
5th Sept. 1936
11th Sept. 1936
20th Sept. 1936
25th Sept. 1936
30th Sept. 1936
5th Oct. 1936
0.0039
0.0021
0.0028
0.0044
0.0056
0.0064
0.0044
0.0048
0.0051
0.0060
0.0060
0.0064
0.0039
0.0046
0.0058
0.0042
0.0052
0.0056
Vitamin A content in ghee in Lovibond Blue. Units per gram.
5th Sept. 1936
11th Sept. 1936
20th Sept. 1936
25th Sept. 1936
30th Sept. 1936
5th Oct. 1936
14.4
13.3
12.2
..
14.3
14.4
15.4
14.4
15.4
14.3
..
15.5
14.3
14.3
..
13.3
14.4
14.4
METHODS
Estimation of carotene.—Carotene has been estimated colorimetrically or
spectrophotometrically in solution after extraction. Barnett [ 1934] and
Gillam [1934] have used spectrophotometric method for the assay of carotene
in butter. De [1935] uses the same method with vegetables. Guilbert
[1934] and Ferguson and Bishop [1934] have used the colorimetric method
for the estimation of carotene in vegetable products. The last method has
been followed in our experiments. For the assay of carotene in grasses and
fodders, the material was finely chopped, dried and then powdered. Two
to ten grams of the material depending on the richness of the carotene content
were digested for one hour under reflux in twenty per cent alcoholic potash.
The flask was then cooled and the contents filtered. The residue was washed
26
Carotene Content of Grasses
with ether-saturated water till the washings were free from colour. The
residues were again extracted with acetone till the extracts were free from
colour. The aqueous and acetone extracts were then extracted with petro-
leum ether, washed with water, dehydrated and made up to a volume. A
colorimetric reading was then taken of the total carotinoid content in a
Lovibond Tintometer, or against a standard bichromate solution. The
carotene content was calculated from Ferguson's curves. The carotinoids
consist of carotene and xanthophyl and the proportions of the two were
determined by the 'methyl alcohol petroleum ether' partition method. In
another rapid method by Pyke [1936] the two processes are combined into
one and the extraction is performed in a mixture of ether and methyl alcoholic
potash solution. The fraction in ether contains the carotene. One hundred mg.
of grass-meal was finely ground and shaken vigourously for five minutes in a
centrifuge tube with 10 c.c. of ether and 3 c.c. of 25 per cent solution of
potassium hydroxide in methyl alcohol. The ether-layer was drawn off,
washed with water and filtered in a sintered glass funnel over anhydrous
sodium sulphate. The process was repeated till there was no more of ex-
traction possible either from the residue or the methyl-alcohol-layer. The
extract was evaporated and the residue dissolved out again in 25 c.c. of
ether and an equal volume of 85 per cent methyl-alcohol. The upper ether-
layer contained the carotene and the lower alcoholic layer xanthophyl. One
or both the methods were tried in the case of grasses and fodders and with
the necessary modification in the case of other feeding materials.
In the case of blood, Palmer's method has been followed. About 5 c.c.
of blood was drawn from the animal and centrifuged to separate the cor-
puscles. 2 c.c. of serum was then mixed with about 8 grm. of Plaster of
Paris. The paste was then extracted with a mixture of 10 c.c. of alcohol
and 5 c.c. of petroleum ether. The extraction was repeated with ether till
no more coloured extracts were obtainable. The ether-extract was then
washed, dehydrated and colour strength matched against a standard bichro-
mate solution to obtain the carotene content.
The carotene content was determined in butter after saponification, on
the unsaponifiable matter.
Six Sindhi young cows of almost equal age and second lactation were
selected for the feeding trials. The following basic ration was given per cow,
each day—
Guinea grass . . . . . . . . . .
Ragi straw . . . . . . . . . .
Groundnut-cake
.
.
.
.
.
.
.
.
.
.
35 lb.
4½ lb.
12 oz.
Concentrate mixture one pound for two pounds of milk-yield per day.
Group A was given the above ration. Group B was fed with 46¼ lb.
of guinea grass and the straw was excluded. Group C was provided with
30 lb. of guinea grass and 6½ lb. of straw. The actual quantity of guinea
J. K. MAKHIJANI AND B. N.
BANERJEE
27
grass consumed was obtained by subtracting the residue from the quantity
provided. The milk-yield was measured each day and the fat percentage
was calculated on weekly averages. A weekly average sample of butter was
used for carotene and vitamin A estimation. The blood was drawn once a
week for carotene estimation.
DISCUSSION AND SUMMARY
Karrer and Schlientz [1934] have shown that carotene from grasses, spinach
and nettles may be regarded as pure β carotene. Smith and Milner [1934]
found leaf (alfalfa) carotene to consist mostly of β carotene. Again β
carotene produces vitamin A in the physiological system in equivalent
amount and α or γ carotene produces vitamin A in only half the amount.
Apparently, therefore, the variation in the form of carotene occurring in
common forage plants is a negligible factor in expressing vitamin A value
from the carotene content.
In the process of drying for analysis with hot air at 45°C. for 24 hours
the carotene loss was very little. Some of the samples that were sent in the
green stage sometimes became a little mouldy and suffered a little loss on this
account. Duplicate trials have proved that the method followed yielded
reliable and concordant results.
In a feeding trial for a short period, it is not possible to deduce any defi
nite conclusions. In a trial on lactating cows it is not possible to measure
the vitamin A reserve before or after the experiment. The stored up vitamin
A is so slowly used up when carotene supply is in deficit, that no detectable
difference can be noted in milk [Schieblisch, 1932]. However, the yellow
value in butter and the carotene content of blood go to show that increased
carotinoid feeding helps to build up reserve of vitamin A in the animal and
a slight increase in the milk supply. Further intensive work is necessary
to solve the many complicated phases of the problem. It would, of course,
be desirable to know which breed of cattle in India produces milk richest in
vitamin content.
We wish to take this opportunity to thank the Directors of Agriculture
of various provinces in India and other gentlemen, too numerous to be in
dividually mentioned here, who very kindly supplied us samples of grasses,
fodders and concentrates. Thanks are also due to Mr. Zal R. Kothavalla,
the imperial Dairy Expert, for this valuable suggestions and criticisms and
to Dr. V. Subrahmanyan, Professor of Biochemistry, Indian Institute of
Science, Bangalore, but for whose co-operation, this work could not have
been undertaken. Dr. G. S. Siddappa very kindly performed a number of
determinations and thus helped us in checking and duplicating many of the
carotene values in this paper to test the accuracy of the methods employed.
28
Carotene Content of Grasses
REFERENCES
Barnett, H. M. (1934). J. Biol. Chem. 105, 259.
Bauman, C. A., Steenbock, H., Beeson, W. M. and Rupel, I. W. (1934). J. Biol. Chem.
105, 167
De, N. K. (1935-36). Ind. Jour. Med. Res. 23, 2, 505 ; 4, 937.
Ferguson, W. S. (1935). Analyst, 60, 680.
Ferguson, W. S. and Bishop, G. (1936). Analyst, 61, 515.
Fraps, G. S., Copeland, O. C. and Traischler, R. (1934). Texas Agri. Expt. Stn. Bull.
495, 5.
Gillam, A. E. (1934). Biochem. J. 28, 79.
Gillam, A. E., Heilbron, I. M., Morton, R. A., Bishop, G. and Drummond, J. C. (1933).
Biochem. J. 27, 878.
Guilbert, H. R. (1934). Ind. Eng. Chem. Anal. ed. 6, 452.
Karrer, P. and Schlientz, W. (1934). Helv. Chim. Acta. 17, 7.
Kniest, K. (1934). C. A. 28, 231.
Palmer, L. S. (1922) A. C. S. Monograph, No. 9.
Pyke, M. (1936). J. S. C. I. 55, 20, 139T.
Ripperton, J. C., Davies, W. C. and Edwards, D. W. (1933). Hawaii Agri. Expt. Stn.
Bull. 65, 58.
Russel, W. C., Taylor, M. W. and Chichester, D. F. (1934). New Jersey Agri. Expt. Stn.
Bull. 560.
Rygh, O. (1934). Biochem. J. 270, 227.
Schieblisch, M. (1932). Chem. Zentr. 1, 1963.
Smith, J. H. C. and Milner, H. W. (1934). J. Biol. Chem. 104, 437.
Watson, S. J. (1935). J. Roy. Agri. Soc. Eng. 95, 103.
Watson, S. J., Bishop, G., Drummond, J. C., Gillam, A. E. and Heilbron, I. M. (1934).
Biochem. J. 28, 1076.
A COMPARATIVE STUDY OF THE COLOSTRUM OF THE
DAIRY COW AND THE DAIRY BUFFALO
BY
V. SIVASUBRAMANIAN, G.M.V.C.
AND
C. W. DOVER, B.Sc. (AG.)
Imperial Dairy Institute, Bangalore
(Received for publication on 17th November 1937)
No study has so far been made of the composition of the colostrum of
buffaloes, and the analysis of the colostrum of the Indian dairy cow has been
made only in the Montgomery breed, by Shah [1936]. In this experiment a
more detailed analysis of the colostrum of cows and buffaloes, than has hitherto
been done by any previous worker, has been carried out with a view to make a
comparative study of the colostrum of these two types of dairy animals.
The most striking difference between normal milk and colostrum is in
the amount of globulin, a protein that occurs in blood and in traces only
in ordinary milk, but is present in colostrum in a comparatively large amount.
This globulin content has been found to correspond perfectly with the amount
of hemolysins in colostrum [Rogers, 1935] and other workers [Mason,
Dalling and Gordon, 1930 and Davies, 1936] have shown that the transmission
of antibodies from the mother to the offspring is through the globulin of
colostrum and that there is no transmission of maternal antibodies through
the placenta.
The animals selected for the investigation were from the two important
Indian dairy breeds maintained at the Imperial Dairy Institute Farm, Banga-
lore, viz., three Sindhi cows and three Murrah buffaloes.
Samples of colos-
trum were taken immediately after calving, and every six hours for the first
day after calving, every twelve hours for the next two days, and after twenty-
four hours on the fourth day, by which time the milk was found to have
become normal. Samples were drawn from all the four quarters of the
udder.
ANALYTICAL METHODS
The determination of the proteins was carried out by the newer methods
of protein analysis suggested by Moir, and adopted by Bergman and Turner
[1937] in their analysis of goats' colostrum.
( 29 )
30
Colostrum of the Dairy Cow and the Dairy Buffalo
The total protein was precipitated by warm trichloracetic acid, thereby
leaving the non-protein nitrogen in solution. After filtering and washing
several times with a dilute solution of trichloracetic acid, the filter paper
and precipitate were transferred to a Kjeldahl flask, and the nitrogen content
was determined by the usual Kjeldahl method.
Casein was precipitated by dilute acetic acid buffered with a solution of
sodium acetate to maintain the pH at approximately 4.0, which is the pH
of casein. The precipitate was filtered and washed with distilled water,
and the filter paper with the precipitate was digested in a Kjeldahl flask to
estimate the nitrogen content as before.
Casein and globulin were precipitated together by the addition of a
saturated solution of magnesium sulphate, after first neutralising the sample
to phenolphthalein with sodium hydroxide. An additional amount of anhy-
drous magnesium sulphate was added to saturate the water in the sample.
After the precipitation was complete, the solution was filtered in a pressure
filter and the residue was washed with a saturated salt solution. The nitrogen
content was determined as for total protein.
The amount of albumin was calculated by subtracting casein and globulin
from total protein, while the difference between casein and globulin and
casein gave the globulin content of the sample.
The specific gravity was determined by the Westphal balance at a tem-
perature of 20°C. ; acidity and chloride by titrating with sodium hydroxide
and silver nitrate respectively ; fat by the Gerber method ; total solids and
ash. respectively by evaporating to complete dryness on a water bath, and
subsequent ashing of the residue ; and lactose by titrating with the sample,
a. 6 per cent copper sulphate solution saturated with a mixture of potassium
thioeyanate, sodium carbonate and sodium phosphate in the ratio of 3 : 6: 10 ;
0.4 grm. of lactose reducing 5 c.c. of the solution.
TABLE I
Composition of the colostrum of Murrah buffaloes
—
Specific, gravity . .
Acidity (c.cs. of N. alkali
required to neutralise 10
C.C.S.)
Chloride (as NaCl) . .
Water . . . .
Total solids . . .
Fat
.
.
.
.
Total protein (N×6.38) .
Casein (N×6. 33) . .
Albumin .
.
.
.
Globulin .
.
.
.
Lactose
.
.
.
.
Ash
.
.
.
.
Coag. on boiling . .
Coag. with rennet . .
No. of hours alter parturition
0
(At
birth)
1.074
0.35
0.01
71.1
28.9
3.9
21.4
6.8
3.8
10.8
2.2
1.1
+
—
6
1.077
0.43
0.80
69.0
31.0
4.0
23.8
7.7
3.6
12.5
2.2
0.9
+
—
Comp.
of 12 &
18
1.065
0.43
Percentages
0.69
68.6
31.4
6.2
18.4
6.1
3.3
9.0
2.4
0.8
+
—
24
1.049
0.33
0.51
78.5.
21 .5
7.3
1.0.9
5.2
3.0
2.7
2.5
0.7
+
—
30
1.040
0.20
0.46
81.4
18 .6
7.6
7.4
4.2
2.2
1.0
2.7
0.8
+
—
48
1.042
0.27
0.41
80.4
19.6
9.3
6.6
4.2
1.6
0.8
3.0
0.7
—
+
60
1.038
0.21
0.36
83 . 4
16.6
7.1
5.3
3.9
1.2
0.2
3.2
0.7
—
+
72
1.036
0.19
0.34
82.8
17.2
7.8
5.1
4.2
0.8
0.1
3.4
0.7
—
+
96
1.035
0.17
0.32
84.0
16.0
7.0
4.4
4.0
0.3
0.1
3.7
0.7
—
+
V. SIVASUBRAMANIAN AND C. W.
DOVER
31
TABLE II
Composition of the colostrum of Sindhi cows
—
Specific, gravity . .
Acidity (c.cs. of N. alkali
required to neutralise 10
c.cs.)
Chloride (as NaCl) . .
Water
.
.
.
.
Total solids . . .
Fat
.
.
.
.
Total protein (N × 6.38) .
Casein (N× 6.38) . .
Albumin .
.
.
.
Globulin .
.
.
.
Lactose .
.
.
.
Ash . . . . .
Coag. on boiling . .
Coag. with rennet . .
No. of hours after parturition
0
(At
birth)
1.063
0.41
0.46
81.8
18.2
2.0
12.8
4.0
2.6
6.2
2.2
1.0
+
—
6
1.053
0.35
0.44
81.1
18.9
2.7
12.5
3.9
2.6
6.0
2.5
0.9
+
—
Comp.
of 12 &
18
1.043
0.32
24
1.038
0.32
Percentages
0.36
83.2
16.8
3.3
9.6
4.0
2.2
3.4
2.7
0.9
+
—
0.33
83.4
16. 6
4.2
8.4
4.0
1.9
2.5
2.8
0.9
+
—
36
1.037
0.29
0.35
85.3
14.7
4.1
6.6
3.6
1.7
1.3
3.0
0.9
+
—
48
1.036
0.25
0.36
87.6
12.4
2.4
5.6
3.4
1.1
1.1
3.4
0.9
+
—
60
1.033
0.23
0.33
87.6
12.4
3.1
4.7
3.4
0.6
0.7
3.5
0.8
—
+
72
1.035
0.22
0.31
88.9
11.1
2.2
4.4
3.5
0.4
0.5
3.7
0.8
—
+
96
1 .033
0.20
0.29
86.8
13.2
4.4
4.0
3.4
0.2
0.4
3.9
0.8
—
+
OBSERVATIONS
From Tables I and II*, it can be observed that the specific gravity
of chloride and total solids are higher in buffaloes' than in cows' colostrum,
and that they decrease in both cases during the progressive change into milk.
Though the acidity and ash content of buffaloes' colostrum are higher than
those of cows' colostrum soon after calving, they decrease more rapidly, and
in normal milk they are slightly lower than in the case of the cow. The
fat percentage of the colostrum of both the animals just after calving is very
low and the increase is not marked by any regularity ; an observation which
has also been recorded by other workers [Rogers, 1935 ; Davies, 1936 and
Richmond, 1930 ].
Buffaloes' colostrum is, however, richer in fat than
cows' colostrum. The lactose content in both the breeds is very low at the
time of calving and it rises steadily as the colostrum changes to normal milk.
It is, however, observed that buffaloes' colostrum contains a lower percentage
of lactose than cows' colostrum.
* Table I represents the average of Murrah buffaloes Nos. 60, 63 and 64 ; and Table II
represents the average of Sindhi cows Nos. 257, 261 and 275.
32
Colostrum of the Dairy Cow and the Dairy Buffalo
The high percentage of total protein in the earliest stages of the colostral
period is due mainly to the high globulin content. Buffaloes' colostrum
shows a higher content of total protein than cows' colostrum, and in both
cases there is a fall which is more rapid during the first twenty-four hours
after parturition than the following days. Both casein and albumin behave
similarly in that they are present in large amounts at the time of calving,
and subsequently show a gradual fall. In these constituents, also buffaloes'
colostrum is richer than cows' colostrum.
The important part which globulin plays in the transmission of anti-
bodies from the mother to her young justifies the separate analysis of this
protein, which has not so far been done in previous investigations on the
colostrum of bovines. Starting at the high figure of 10.9 per cent in buffaloes
and 6.2 per cent in cows, it falls abruptly within the first twenty-four hours
by about 75 per cent in the former and 50 per cent in the latter. The rapidity
of the subsequent fall, though not as great as in the beginning, is sufficient
to result in only traces of this protein fraction being left in the normal milk.
SUMMARY
1. Buffaloes' colostrum is higher in specific gravity, acidity, sodium
chloride, total solids, total protein, casein, albumin, globulin and ash than
cows' colostrum, while in lactose it is lower.
2. In both animals there is a progressive fall in all the constituents
except lactose which shows an increase and fat which is irregular.
3. Globulin constitutes the major part of the total protein of both kinds
of colostrum soon after calving, and its decrease is more marked during the
first twenty-four hours after parturition than during the remainder of the
colostral period.
4. Buffaloes' colostrum changes to normal milk in about three days,
while cows' colostrum takes about four days.
ACKNOWLEDGMENTS
We are grateful to Mr. Zal R. Kothavalla, Imperial Dairy Expert to
the Government of India, for suggesting the investigation and our thanks
are also due to Messrs. S. Cox and H. C. Verma of the Imperial Dairy Insti-
tute, Bangalore, for providing us the necessary facilities.
REFERENCES
Associates of Lore A. Rogers (1935). Fundamentals of Dairy Science. pp. 466-468,
Borgman, A. J. and Turner, C. W. (1937). J. of Dairy Sci. 20, 1, 39-40.
Davies, W. L. (1936). The Chemistry of Milk, pp. 39 and 450-452.
Mason, J. H., Dalling, T. and Gordon, W. S. (1930). J. of Path. and Bact. 33,783.
Richmond, H. D. (1930). Dairy Chemistry, pp. 312-313.
Shah, A. A. (1936). Ind. Jour. of Vet. Sci. & Anim. Husb. 6, 3, 234-237.
THE INCIDENCE OF SALMONELLA ENTERITIDIS VAR
DUBLIN IN PYOSEPTICAEMIA OF CALVES IN INDIA*
BY
V. R. RAJAGOPALAN, G.M.V.C.
Assistant Veterinary Research Officer, Imperial Veterinary Research Institute,
Mukteswar
(Received for publication on 9th January 1938)
THE writer is indebted to Mr. Shirlaw for the material which forms the
subject of this determinative study. The culture was received in the form
of two agar-slants with a request to have it typed, and it was followed with
the following history :—" This is an organism which has recently been isolated
from a specific enteritis of calves, and the work which we have done so far
in this laboratory, up-to-date, would seem to indicate that this organism
is of primary pathological importance in this disease" The pathology
of this disease has been recorded by Shirlaw [1935]. He has also sent a further
note [Shirlaw, 1936] on the identity of the organism, based on our report.
On receipt, the organism was put to a complete morphological and cul-
tural test. The result was as follows : Morphology (in nutrient broth after
24 hours incubation at 37°C.) :—Short Gram-negative rods, 0.9 to 1.6 µ.
in length, and 0.6 to 0.7 µ, in breadth, with parallel or slightly bulging
sides. Their ends are rounded and axis straight. They are arranged
in singles and occasionally in pairs. Endospores and capsules are not formed.
They are actively motile by means of peritrichate flagella. Stained by Leish¬
man-stain, most of the elements take a remarkably bipolar staining.
Description of Single Colonies.—Grown on plain-agar plates at 37°C.
for 24 hours, colonies are circular in shape with a smooth surface and an
entire margin. They measure 1.5 to 2 mm. in diameter. They are low-
convex and are easily emulsified forming a homogeneous emulsion when
rubbed up with a drop of water. They are buterous in consistency, are
glistening and are transparent.
Description of growth on stroke.—Grown on plain-agar slants at 37°C.
for 48 hours, a moderate slightly spreading growth takes place. The edges
are slightly spreading and undulate. Its surface is moist and has a beaten-
copper appearance over the tract of the needle and a somewhat scally appear-
ance over the spreading margin. On old agar-slants the surface has an
oily sheen, but there is no irridescence.
Slab growth in gelatin.—Growth along needle tract.
On potato, growth is moderately rich and has no colour.
It is an aerobe and a facultative anaerobe.
* Paper read at the Indian Science Congress, Calcutta, 1938.
( 33 )
F
34
Pyosepticaemia of Calves in India
Fermentation of Carbohydrates.—The following are fermented with the
production of acid and gas :—Dextrose, maltose mannitol, xylose, dulsitol,
dextrin, sorbitol, rhamnose, glucose, galactose, laevulose, mannose and
trehalose. Acid is produced in starch. Lactose, sucrose, salicin, inocitol,
glycerol, inulin, rhaffinose, adonite and arabinose are not attacked.
Other biochemical reactions.—Litmus-milk is rendered slightly acid in
24 hours, but later becomes alkaline. Tested for Indol in 1 per cent peptone
water after 5 days' growth, using Bohme's reagents, a faint colour appears
which disappears with time. It is negative for the Voges-Proskauer test,
but positive for the methyl-red test. It reduces nitrates, produces hydro-
gen-sulphide and is positive for catalase and methyline blue reductase.
The morphological, cultural and biochemical characters are typical
of the salmonella group and resemble those of S. enteritidis, S. newport, S.
dar-es-salaam, S. stanley and certain other members of the salmonella group.
A preliminary agglutination test was undertaken to ascertain which of the
various heat-stabile somatic antigens occurring in the salmonella group was
concerned in the organism under study.
The serum for this agglutination test was obtained as follows : the
Shirlaw's organism was grown in plain agar in a Petri-dish for 24 hours. It
was then washed with normal saline solution containing 0.1 per cent of for-
malin. It was then adjusted to an opacity of 300 million bacteria per c.c.
with saline containing 0.1 per cent of formalin. This emulsion was injected
intravenously, after a storage of 3 days at room temperature, into a rabbit
five times at intervals of five to six days. The doses for the successive in-
jections were 0.1 c.c., 0.5 c.c. for the first and second injections respectively,
and 1 c.c. for the subsequent three injections. The rabbit was bled for serum
on the ninth day after the last injection. Its titre then was over 12,000,
the end titre not having been determined.
The heat-stabile antigens were made according to the technique
of Bruce-White [1926]. Roux flasks containing agar with a 1 : 800 con-
centration of phenol, were sown with the selected cultures. After an
incubation of 48 hours, the cultures were washed in 0.1 per cent saline and
heated in a water-bath at the boiling point for about thirty to forty minutes.
The opacity of the emulsions was then made up to 200 million bacteria per
c.c. and formalin was added to give a concentration of 0.1 per cent.
The serum was diluted in series in such a manner, that, when an equal
quantity of the bacterial emulsion was added, the final dilution of the serum
in the successive tubes became 25, 50, 100, 200, 400, and 800 respectively.
The strains were selected for this test so that all the somatic factors
then known to occur in the salmonella group were represented.
The test was conducted in the water-bath at 55°C. and readings were
taken at the end of four hours and twenty-four hours. The results are tabu-
lated in Table No. I.