NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
14
isolated houses to investigate its action on rats under natural conditions. The
investigation should be made by some one familiar with the use of the gas.
Cost of Disinfection.
I.—Disinfection of clothes.—As we have stated above, an air-tight godown
must be built with arrangements for letting the gas play on the clothes for, say,
fifteen minutes and then turning off the supply of gas to allow of safe entry to the
building. This would be necessary if the clothes are to be returned to their
owners in a reasonable time. The advice of an engineer is requisite for the con-
struction of the godown as the danger from the gas is not to be underrated. The
price of the chemicals is slight.
The cost of potassium cyanide (98—100 per cent.) is 1 shilling per lb. for
28 lbs., or 99 shillings a cwt. if bought in bulk (Merck's quotation). The cost of
sulphuric acid is 1d . ( o n e p e n n y ) p e r l b . i f c a r b o y s a r e b o u g h t ( B a i r d &
Tatlock's quotation).
Suppose the room was of 1, 000 cubi c feet capaci ty and moderatel y ai r-ti ght, 7½
ozs. of potassium cyanide and 15 ozs. of sulphuric acid would be required.
The total cost of chemicals for disinfection would be between 6 pence and 7 pence
plus the pay of a supervisor. China vessels to hold the chemicals would last
indefinitely.
II.—Cost of disinfecting houses.—We have got a machine adapted for
experiments in single rooms and we could use it for experiments on houses with
natural burrows. Some extra lengths of tubing might be necessary, but the cost
would not be great.
The conclusion then is that so far as disinfection of clothes is concerned we
have in hydrocyanic acid gas a very cheap and efficient pulicide. With a specially
constructed godown, it would be possible to deliver over to their owners clothes
absolutely free of fleas in half-an-hour. There would be no damage to fabrics.
If proper precaution is taken and an experienced man acts as supervisor no
accident should occur.
With regard to the disinfection of houses the conclusions arrived at are not
so satisfactory. We desire permission to use this gas in isolated huts with natural
burrows. With artificially constructed burrows good results have been obtained.
If as satisfactory results can be got with natural burrows we have an efficient
means of clearing houses of plague rats and fleas. But the means are not without
danger. This danger could be largely guarded against in isolated houses with a
clear space round them, or in an aggregation of houses with a clear space round
them, as in a village, if evacuation of the houses could be insisted on till such time
as occupation be declared safe. In crowded localities, as in tenements in cities,
the danger is too great to permit employment of the method.
15
Experiment I. *
A.
Fleas and rats were placed in the small room described on page 9 of 830
cubic feet capacity. 170 grammes of 98 per cent. potassium cyanide, equivalent
to about ¾ oz. of the salt to 100 cubic feet air space, was decomposed outside
the room. The resultant gas calculated to be about 2.19 cubic feet at 26° Centi-
grade was led into the room by tubes without the use of a fan to drive it in. The
generation of gas took 51 minutes.
The object of this experiment with fleas was to test the penetration of gas
through various layers of cloth stuffs.
Details of covering, etc.,
enclosing the fleas.
Results after 51 minutes'
exposure to the gas.
REMARKS.
(a) 15 fleas were put in a white cotton
bag and that again enclosed in
one bag of coarse red blanket.
(a) All fleas were
found dead.
( b ) 9 fleas in a white cotton bag were
enclosed in two layers of coarse
red blankets.
( b) Do.
(c) 11 fleas in a white cotton bag were
enclosed in three layers of coarse
red blankets.
(c) 10 dead ; 1 alive.
(d) 11 fleas were put in a fine flannel
bag.
(d) All fleas dead.
(e) 9 fleas were put in a chintz bag
( e ) Do.
(f ) 10 fleas were put in a cashmere bag (f) Do.
(g) 20 fleas were put in a single chintz
bag and that rolled in a durree,
blanket, coat and trousers.
(g) 7 escaped; 12
alive; 1 dead.
* NOTE.—In Experiments I to IX inclusive the potassium cyanide was stated to be of 98 per cent. strength.
16
Experiment I— contd.
B.
Rats and fleas were put in various positions on the floor—the rats in cages
and the fleas in test-tubes with the glass end removed and both ends covered by
some netting to allow of proper diffusion of the gas.
POSITION.
RATS.
FLEAS.
REMARKS.
Dead. Sick. Alive.
Dead.
Alive.
On the floor
. . ...
1
2
...
. . .
4 feet from floor
. 2 ...
1
. . .
. . .
7 do.
.
. ...
1*
. . .
All
...
*Escaped, but found
outside sick.
10 do.
. .
. . .
1 2
All
...
15 do.
. . ..
1 2
All
...
C.
Twenty fleas were placed in each of four cages,—two containing sand at
the bottom and two bran. At the end of 51 minutes the cages were examined
and guinea-pigs put into the cages on three separate occasions to recover the fleas.
CAGES.
No. of fleas
put into each
cage.
Result, i.e., recovered alive
after exposure of 55
minutes.
REMARKS.
Cage No. 1 with
bran at the
bottom.
20
4
Cage No. 2 with
bran at the
bottom.
20
None.
Cage No. 1 with
sand at the
bottom.
20
2
Cage No. 2 with
sand at the
bottom.
20
2
For a control to this, see the end of Experiment III.
17
Experiment II.
A small room was used—of 830 cubic feet capacity. The same amount of
hydrocyanic acid gas as in Experiment I was introduced without the use of
a fan. The exposure to the gas was for half-an-hour only.
POSITION.
RATS.
FLEAS.
REMARKS.
Dead. Sick.
Alive.
Dead.
Alive.
On the floor
.
.
1
. . .
1
...
. . .
4 feet from floor
.
1
. . .
2
All
...
6 do.
.
.
. . .
2
. . .
. . .
. . .
10 do.
.
.
...
2
...
All
. . .
12 do.
.
. ...
1
. . .
All
. . .
Experiment with Fleas.
Details of covering, etc., enclosing the fleas.
Results after 30
minutes' exposure
to the gas.
REMARKS.
(a) 11 fleas were put in a white cotton
bag and that again enclosed in one
bag of coarse red blanket.
(a ) 9 alive; 2 dead.
Another cotton bag
containing 11 fleas
was put between
two layers of blan-
ket and two of cre-
tonne—all dead. In
this case a pipe dis-
charged the gas on
the top of the
blanket.
( b ) 12 fleas in a white cotton bag were
enclosed in two layers of coarse
red blanket.
( b) 7 alive; 5 dead.
(c ) 12 fleas in a white cotton bag were
enclosed in three layers of coarse
red blanket.
(c) 10 alive; 2 dead.
( d) 17 fleas were put in a fine flannel
bag.
( d) All dead.
(e ) 14 fleas were put in a chintz bag
. ( e) All dead.
(f ) 15 fleas were put in a cashmere bag . ( f) All dead.
(g) 10 fleas were put in a single cotton
bag and that rolled in a durree,
blanket, coat, and trousers.
(g) All alive.
18
Experiment III.
A small room of 830 cubic feet capacity was used. 340 grammes of 98 per
cent. potassium cyanide, equivalent to about 1½ ozs. of the salt to 100 cubic feet
air space, was decomposed outside the room. The resultant gas, calculated to
be about 4.38 cubic feet at 26° Centigrade was delivered into the room by means
of a fan. Exposure for 20 minutes.
Details as to conditions under which the
fleas were admitted to the action
of the gas.
Results of fumigation.
REMARKS.
(1) 10 fleas in a cotton bag wrapped
in several layers of blanket
and thick sheet.
(1) All dead . . In all these results the
fleas were kept for two
hours and looked at
again—in no case did
any flea show signs of
life.
(2) 8 fleas in a bag at the foot of a
box containing boots, deck-
shies (copper vessels), and
some clothing.
(2) All dead.
(3) 9 fleas in a bag wrapped in a
durree, blanket, and coat roll-
ed tightly up.
(3) 8 alive; 1 dead . Control fleas kept in
bags in precisely the
same conditions as
those shown herein
were found at the end
of two hours to be all
alive.
(4) 9 fleas in a cotton bag on top of
a box.
(4) All dead.
(5) 8 fleas in a cotton bag wrapped
up in a durree and 3 blankets,
fairly tightly rolled up—a pipe
discharging gas was put at
the mouth of the roll.
(5) All dead . . 4 cages, 2 with bran
and 2 with sand at the
foot, were placed on
the floor. 20 fleas
were put in each.
After fumigation
guinea-pigs were put
three times into each
box. No fleas were
recovered, so presum-
ably all were killed by
the gas.
(6) 9 fleas in a cotton bag hanging
5½ feet from the floor.
(6) All dead.
(7) Bag 'A' as in Experiments I and
II, that is, 8 fleas in a cotton
bag enclosed in a red blanket
bag 5½ feet from the floor.
(7) All dead.
(8) Bag 'B,' same as above, but two
layers of blanket bags.
(8) 7 fleas; all dead . In control cages guinea-
pigs were put in; re-
covered 21 out of 40
fleas from the 2 sand
cages, and 19 out of
40 from the 2 bran
cages.
(9) Bag 'C,' same as above, but three
layers of blanket bags on the
floor.
(9) 8 fleas; all dead.
(10) 8 fleas in a test-tube on the
floor.
(10) 8 fleas; all dead.
19
Experiment IV.
In disinfection of boxes do the clothes need to be taken out of boxes and
hung up; or can we thoroughly disinfect clothes by leading pipes into the
boxes ?
Two experiments were done on this point.
The same amount of hydrocyanic acid gas as in Experiment III was pumped
into the small room of 830 cubic feet capacity (about 4.38 cubic feet). The
exposure was for 20 minutes. The room was entered in 30 minutes from
commencement of operations. By using the test rod a good prussian blue tint
showed that a concentrated gas was passed into the room. Nine pipes took the
gas into the room from the generating chamber outside. One pipe was led into
the bottom of Box I. Two pipes were led into the bottom of Box II.
In Box I from above downwards fleas were put in the following positions:—
PARTICULARS.
Result.
REMARKS.
A.—9 fleas were in a bag covered by
coat, trousers, durree, and blan-
ket.
All 9 alive.
B.—Lower down rug, 4 blankets, 1
chudder, and durree, then the
bag with 8 fleas.
All 8 alive.
C.—Then a great-coat and 10 fleas
below in a cotton bag.
9 alive; 1 dead.
D.—Then a military blanket, then
7 fleas in bag ; then a rug on
bottom of box.
4 alive; 3 dead.
In Box II from above downwards fleas were put in the following positions :—
PARTICULARS.
Result.
REMARKS.
A.—Rug, then bag containing fleas . All dead
.
. No. 2 box much less
tightly packed than
No. 1 box.
B.—Blanket, pillow, and then bag
containing fleas.
All dead.
C.—Pillow and rug, then bag con-
taining fleas.
All dead
. . 20 fleas in 4 boxes, 2 with
sand at the bottom and 2
with bran, as before.
None recovered ; all
present dead presumably.
D.—Pillow and rug, then bag con-
taining fleas ; 2 pillows at foot
of box.
All dead.
D 2
20
Experiment V.
With Clothes in Boxes.
Same period of exposure 20 minutes. The same amount of hydrocyanic
acid gas (about 4.38 cubic feet) as in Experiment III was introduced into the
room of 830 cubic feet capacity by means of a fan.
Box I, from above downwards.
PARTICULARS.
Result.
REMARKS.
1 . R u g a n d c h u d d e r , t h e n c o t t o n b a g
with 10 fleas in it.
10 fleas; all dead.
2. Then durree and 2 blankets with
bag of 7 fleas below.
7 fleas; all dead.
3 . T h e n o n e b l a n k e t , w i t h b a g o f 9
fleas below.
9 fleas; all dead.
4. Then a blanket in several folds
and a bag with 7 fleas below it.
7 fleas; all dead.
5. Then another blanket with 9 fleas
below in a bag.
9 fleas; all dead.
Box II.—Two pipes were led into Box II, from above downwards.
PARTICULARS.
Result.
REMARKS.
(a) Pillow, then 10 fleas in bag . 9 dead; 1 just feebly
living.
The pipes were led into
foot of box. Those fleas
which were found "feebly
living" at the end of
experiment remained so
for 1½ hours after the
experiment.
(b ) One rug and 9 fleas in bag below
it.
6 dead; 3 feebly
living.
(c) Then rug and blanket with 8
fleas in bag.
8 dead, all.
(d ) Then rug and pillow with 10
fleas in bag below.
10 dead, all
21
Experiment VI.
Does the gas kill cultures of micro-organisms and what effect has it on the
germinating power of grains ? Does it render dry food-stuff poisonous?
The small room of 830 cubic feet capacity was used. About 4.38 cubic
feet of hydrocyanic acid gas was introduced by a fan and allowed to act 20
minutes from the start. The test rod showed plenty of gas to be present.
The grains tested were: (I) Bajri, (2) , Wheat, (3) J owari, (4) Mula or
Radish, and (5) Rice.
(I), (2), and (5) were put in kerosine oil tins. A pipe conveying the gas
was conducted to the bottom of the mass and one was directed on the surface.
Mula and jowari were in small amounts and gas played on their surface from
pipes directly placed on them.
I . W e r e t h e g r a i n s p o i s o n o u s ?
No. Tested on monkeys, rabbits, guinea-pigs, hens, and pigeons. Fed
on it for 24 hours. None dead nor ill. Again chapatis were made of the
wheat, jowari, and bajri, and monkeys and hens were fed on them. No ill
results.
II. The germinating power of the seeds was not affected. Certain quanti-
ties of the above grains were planted and seeds not subjected to the gas were
planted at the same time to serve as control in the comparison of the rate of
growth.
Both examples of bajri, jowari, and mula grew well; of wheat grew feebly,
because much of it was husked.
Cultures of (a) Micrococcus melitensis, (b) Cholera spirillum, and ( c) Bacillus
anthracis, were placed in the room, but the cotton-wool stoppers were not removed
from the test-tubes containing the cultures as it was thought not to be safe to
do so. They were after subjection to the gas re-transplanted on agar and
showed good growths.
Test-tubes containing cultures of ( a ) Streptococci, ( b ) Bacillus typhosus,
(c) Bacillus coli communis, and ( d) Bacillus pestis, were placed in the room
with their cotton-wool plugs removed, so that the gas had full action on the
germs. After the experiment the germs were recultured on agar. The Bacillus
pestis was overgrown with some yellow contaminating organism. The others
grew well and seemed to the naked eye to be pure cultures.
So probably the above germs are not affected by the gas.
Fleas after 5 minutes' exposure to the gas were found dead. They were
put into tubes and withdrawn after 5, 10, and 15 minutes' exposure, all dead.
22
Experiment VII.
The following experiments—VII, VIII, and IX—were performed in the large
room. Description of room and burrows will be found on pages 11 et seq. The
cubic capacity is about 1,640 cubic feet. In Experiment VII the gas was deliver-
ed into the room without fan by tubes led from flasks outside the room. Potassium
cyanide of the strength of 98 per cent. to the amount of 255 grammes (equiva-
ent to about .56 ozs. of the salt to 100 cubic feet air space) was decomposed.
The resultant hydrocyanic acid gas was calculated to be about 3.28 cubic feet
at 26° Centigrade.
In 10 minutes after the cyanide and acid were mixed sufficient gas was
evolved to give a decided result with the test rod.
The exposure to the gas was for 45 minutes.
POSITION.
RATS.
FLEAS.
REMARKS.
Dead. Sick.
Alive.
Dead.
Alive.
Rats on wall
.
.
3
3
1
20 (all)
. . .
Hanging from rafters
...
1
1
All
. . .
(10—15 feet).
15 feet from floor
.
...
...
1
All
. . .
The tubes were introduced into the burrows 1½ feet.
Burrow A
.
.
. ...
...
1
..
All.
For description of
burrows, see page
12.
„ B
.
.
.
. . .
...
1
...
All.
„ D .
.
.
...
...
1
...
All.
Fleas were placed in 4 cages, 2 of bran and 2 of sand on the floor.
CAGES.
No. of fleas put
into each
cage.
Results, i.e., recovered alive
after 45 minutes'
exposure.
REMARKS.
Cage No. 1 with
bran.
40
1 was recovered after fumi-
gation.
The counts were
made by means of
guinea-pigs in all
these cases.
Cage No. 2 with
bran.
20
None recovered.
Cage No. 1 with
sand.
20
12 were recovered
.
. For a control to
this see the end
of Experiment III.
Cage No. 2 with
sand.
20
14 were recovered.
In this experiment the gas proved so light that it was most effective at the
upper levels of the room; many fleas in cages on the floor escaped, especially
those in cages with sand at the bottom in which they buried themselves. Both
fleas and rats in the burrows escaped, even although the tubes were led into the
burrows a little distance.
23
Experiment VIII.
Another experiment was tried with the following alterations: (1) the fan was
worked; (2) the tubes leading off from the main tube were larger in calibre and
their total surface area equal to the surface area of the large tube leading from
the generator, so that the full amount of gas was delivered into the room. There
were nine pipes altogether: five delivered into the room at different heights and
four were inserted into the four burrows, and the mouths of the burrows where
the pipes were inserted were choked up.
Three hundred and forty grammes of 98 per cent. potassium cyanide was
decomposed. The resultant hydrocyanic acid gas calculated to be about 4.38
cubic feet at 26° Centigrade was delivered into the room of about 1,640 cubic feet
capacity. The amount of potassium cyanide used would be equivalent to about
¾ oz. to 100 cubic feet air space. There was 35 minutes' exposure to the gas.
By means of the observation rods the room was seen to be sufficiently free
from the gas five minutes later. Forty minutes, therefore, were taken for the
whole experiment. After the fumigation the fleas were examined at once and also
three hours later to see whether they had revived.
POSITION.
RATS.
FLEAS.
REMARKS.
Dead. Sick.
Alive.
Dead.
Alive.
On the floor
.
.
3
...
1 28 (all)
...
4 feet from ground
.
3
...
1 12 (all)
...
6 do.
.
2
...
...
...
...
8 do.
.
2
...
...
...
...
12 do.
.
3
...
...
10 (all)
...
On the rafters
.
.
. . .
. . .
. . .
11 (all)
...
Burrow A
.
.
.
1
. . .
. . .
15 (all)
. . .
For description of
burrows, see page
12.
„ C .
.
.
1
...
. . .
11 (all)
..
„ D.—Obstruction
in pipe
found.
...
...
1
...
12(all) 20 fleas were put
in each of the four
cages (2 of sand
and 2 of bran).
„ B.—Observation
burrow
opened in
midst of
experiment.
...
1
...
10 (all)
...
After fumigation,
none were recover-
ed by guinea-pigs,
and therefore were
presumably killed.
For control, see
Experiment III.
24
Experiment IX.
Into the same room of about 1,640 cubic feet capacity about 6.57 cubic feet
of hydrocyanic acid gas were introduced, equivalent to about 1.2 ozs. potassium
cyanide to 100 cubic feet air space. The exposure was for 40 minutes. Rats
were let loose on the floor and put loose into the burrows to simulate natural
conditions.
The gas was driven into the room by the fan. The disposition of pipes was
similar to that in Experiment VIII.
POSITION.
RESULTS.
REMARKS.
Dead.
Sick.
Alive.
6 on the floor
.
.
3
1
2
For description of
burrows, see page 12.
Burrow A,
3 put in
3
. . .
. . .
Blind
burrows.
Burrow B,
3 put in
3
...
...
Burrow C, 4 put in .
.
1
. . . 3 escaped.
Burrow D, 3 put in
.
2
. . . 1 escaped.
25
Experiment X.
The following experiments—X, XI, and XII— were made without the use of fan
E
or tubes. The gas was produced in the room itself. First of all the sulphuric
acid (commercially strong, specific gravity 1.83) was mixed with water (2 parts
of sulphuric acid to 4 parts of water) generating heat. The mixture was made in
a china vessel when small amounts were used and in a kerosine oil tin when large
amounts were necessary. Then one part of potassium cyanide (100 per cent.
Burgoyne Burbidges' Double Salt, for analysis see pages 2 and 3 of Report) was
put in and the room at once quitted and the door shut.
In Experiment X a small, very air-tight godown was chosen, of about 346
cubic feet capacity.
One oz. potassium cyanide 2 ozs. sulphuric acid and 4 ozs. water were mixed.
The exposure was for 40 minutes. The doors were then opened, but fumes of
gas still were seen o be coming off.
The room was entered 15 minutes later. The fleas were examined at once
and also two hours later.
POSITION.
FLEAS.
REMARKS.
Dead.
Alive.
15 fleas in a muslin bag 8 feet
from the ground.
15
...
6 fleas in a flannel bag on the
floor.
6
. . .
9 fleas in a cashmere bag . .
9
. . .
10 fleas in a cotton bag enclosed
in one rough blanket bag 5 feet
from floor.
1 0
...
7 fleas in a cotton bag enclosed
in two blanket bags 5 feet from
floor.
7
. . .
11 fleas in a cotton bag enclosed
in three blanket bags.
11
. . .
26
Experiment X— contd.
A box was put into the room with fleas in bags in different positions.
POSITION.
Result.
REMARKS.
On the top of all was a bag with 8 fleas
8 dead (all)
.
. 50 fleas were put in
each of 4 cages, 2
with sand at foot
and 2 with bran.
After the fumigation
was over flea counts
were made on
guinea-pigs three
times at intervals
of several hours and
none were recover-
ed. All, therefore,
were presumably
killed. For controls,
see the end of
Experiment III.
Then came a durree, trousers, and a coat
in folds.
Then came No. 2 bag with 10 fleas
. Immediately after the
godown was opened
all the fleas looked
dead, but two hours
later 4 were found
dead and 6 alive.
Then came a pair of trousers; a coat, and
a durree.
Then No. 3 bag with 7 fleas .
.
.
4 alive ; 3 dead.
Then came several layers of a chudder
with No. 4 bag below it.
9 (all) living two hours
after opening the
godown.
Then came a blanket in 8 layers with No.
5 bag below.
7 alive ; 3 dead, two
hours after opening
the godown.
Then several layers of a rug with No, 6
bag below.
5 dead ; 4 alive, two
hours after opening
the godown.
27
The following experiments—XI and XII—were made to determine whether the
simple process above described would disinfect the large room of 1,640 cubic feet
capacity described on pages 11 et seq., containing burrows, so dispensing with
the fan and complicated arrangements of generator and tubes. It will be seen
that the burrows were not penetrated even with the 1 oz. of KCN to 100 cubic
feet used in Experiment XII.
Experiment XI.
Eight ozs. of potassium cyanide (Burgoyne Burbidges' Double salt 100
per cent.) 16 ozs. of sulphuric acid specific gravity 1.83 and 32 ozs. of water
were mixed—a proportion of about ½ oz. to 100 cubic feet.
The exposure was for 50 minutes. Fifteen minutes later the room was
entered and was examined at once on opening the godown and also three hours
later.
POSITION.
RATS.
FLEAS.
REMARKS
.
Dead. Sick.
Alive.
Dead.
Alive.
On the floor
.
.
2
1
1 20 (all)
dead.
...
4 feet from the floor . ...
. . .
2
8 dead
...
5 do.
.
5
...
. . . 30 dead
. . .
6 do.
.
1
. . .
. . .
...
. . .
10 do.
.
1
...
2
21 dead
5
Rafters
.
.
. ...
...
. . .
8 dead
6
Burrow A Blind
burrows.
...
...
1
...
7 For description of
burrows, see page
12.
„ B
...
...
1
...
7
„ C Two way
burrows.
...
...
1
...
8
„ D
. . .
...
1
...
7
28
Experiment XII.
Same room. 16½ ozs. of potassium cyanide (same salt as in Experiments
X and XI), 32 ozs. of sulphuric acid of specific gravity 1.83 and 64 ozs. of
water—about 1 oz. of KCN to 100 cubic feet of space. Exposure 50 minutes.
POSITION.
RATS.
FLEAS.
REMARKS.
Dead. Sick.
Alive.
Dead.
Alive.
On the floor
.
.
1
2
1 2 1
. . .
4 feet from floor .
.
2
1 2
9
...
6 do.
.
.
3
...
1
35
. . .
10 do.
.
.
2
...
1 16
2*
* These appeared
dead on opening
the godown, but
recovered 3 hours
later.
Rafters
.
.
.
. . .
. . .
...
2
9
Ledge near open space
between roof and
smaller end wall.
...
. . .
. . .
7
2
Burrow A
Blind bur-
rows.
. . .
...
1
. . .
6 (all)
For description of
burrows, see page
1 2 .
„ B
. . .
...
1
. . .
9 (all)
„ C
Two way
burrows.
. . .
...
1
. . .
9 (all)
„ D
. . .
. . .
1
. . .
8 (all)
CALCUTTA : PRINTED BY SUPDT. GOVT. PRINTING, INDIA, 8, HASTINGS STREET.
(NEW SERIES)
No. 38.
SCIENTIFIC MEMOIRS
BY
OFFICERS OF THE MEDICAL AND SANITARY DEPARTMENTS
OF THE
GOVERNMENT OF INDIA
PRELIMINARY REPORT ON . THE KILLING OF RATS AND RAT FLEAS
BY HYDROCYANIC ACID GAS.
BY
CAPTA[ILL] D. H. STEVENSON, M.B., I.M.S
.
([ILL] Bacteriological Laboratory.)
ISSUED UNDER THE AUTHORITY OF THE GOVERNMENT OF INDIA
BY THE SANITAR COMMISSIONER WITH THE GOVERNMENT
OF INDIA
CALCUTTA
SUPERINTENDENT GOVERNMENT PRINTING, INDIA
Price annas 8 or 9d.
IP/16/PI.4
REPORT
ON THE WORKING OF THE
GOVERNMENT MEDICAL SCHOOL, RANGOON
FOR THE YEAR 1907
RANGOON
OFFICE OF THE SUPERINTENDENT, GOVERNMENT PRINTING, BURMA
1 9 0 8
[ P r i c e , — R e . 0 - I - 6 = I ½ d . ]
REPORT
ON THE WORKING OF THE
GOVERNMENT MEDICAL SCHOOL, RANGOON
FOR THE YEAR 1907
RA N GOON
OFFICE OF THE SUPERINTENDENT, GOVERNMENT PRINTING, BURMA
1908