NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
Index.
Re—Ve.
Recruitment—
Paras., etc.
Indian other ranks . . . . . . . . .
Register of sick and lame animals—
consolidated, maintenance of . . . . . . . . .
to be maintained for each unit or detachment
.
.
.
.
Remount Depots—
veterinary officer in charge of veterinary hospital of . . .
Reports and Returns—
annual statistical, of units transferred to another district, how
prepared . . . . . . . . .
confidential reports on veterinary personnel
.
.
.
.
.
outbreak of contagious and infectious disease
.
.
.
.
rendered by I. A. V.
C.
.
.
.
.
15 & Appx.
transfer of copies of the last monthly returns of unit and detachment
transferred to another station . . . . . . . . .
Reserve—
of V. Os. . . . . . . . . . . . . .
Rinderpest—
apparatus for inoculation . . . . . . . . .
immunization of animals . . . . . . . . .
S
School, Army Veterinary . . . . . . . . .
Section, I. A. V. C. . . . . . . . . .
Sera—
supply of, to Military Farms Dept. . . . . . . . . .
Slaughter animals—
inspection of . . . . . . . . .
Stere accounts . . . . . . . . .
Syllabus—
of examination for promotion of Veterinary Assistant Surgeons
(W. O.) to Jemadar
.
.
.
.
.
.
.
.
.
Appx.
T
Training—
of I. A. V. C. combatant personnel . . . . . . . . .
V
Veterinary Assistant Surgeons—
appointment . . . . . . . . .
examination for promotion . . . . . . . . .
leave and furlough
.
.
.
.
.
.
.
.
.
12 & Appx
posting . . . . . . . . .
private practice . . . . . . . . .
promotion . . . . . . . . .
Veterinary Officer—
in charge of veterinary hospitals of remount depôts, duties of .
25
32
32
5
33
11
36
II.
17
10
41
41
7
23
21
18
19
VI.
26
24
24
V.
24
35
24
5
39
GIPC—M—VI-5-(71)—3-4-25—850,
CALCUTTA
GOVERNMENT OF INDIA PRESS
8, HASTINGS STREET
No. 38.
( NEW SERIES )
SCIENTIFIC MEMOIRS
BY
OFFICERS OF THE MEDICAL AND SANITARY DEPARTMENTS
OF THE
GOVERNMENT OF INDIA
PRELMINARY REPORT ON THE KILLING OF RATS AND RAT FLEAS
BY HYDROCYANIC ACID GAS.
BY
CAPTAIN W. D. H. STEVENSON, M.B., I.M.S.
( Bombay Bacteriological Laboratory .)
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BY THE SANITARY COMMISSIONER WITH THE GOVERNMENT
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SCIENTIFIC MEMOIRS
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OF THE
GOVERNMENT OF INDIA.
PRELIMINARY REPORT ON THE KILLING OF RATS AND RAT FLEAS
BY HYDROCYANIC ACID GAS.
BY
CAPTAIN W. D. H. STEVENSON, M.B., I.M.S.
(Bombay Bacteriological Laboratory .)
ISSUED UNDER THE AUTHORITY OF THE GOVERNMENT OF INDIA
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List of numbers of Scientific Memoirs by Officers of the Medical and
Sanitary Departments of the Government of India (New Series)
published previous to the present issue.
No. 1. Standardisation of Calmette's Anti-Venomous Serum with Pure Cobra Venom :
the Deterioration of this Serum through keeping in India, by Captain G. Lamb,
I. M. S. and Wm. Hanna, Esq., M.B. Price As. 3 or 4 d.
No. 2. Malaria in India, by Captain S. P. J ames, I.M.S. Price Re. 1-8 or 2s . 3d.
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G. Lamb, I.M.S., and Wm. Hanna, Esq., M.B. Price As. 5 or 6d.
No. 4. On the Action of the Venoms of the Cobra and of the Daboia on the Red Blood
corpuscles and on the blood plasma, by Captain G. Lamb, I.M.S. Price As. 8
or 9d.
No. 5. Specificity of Anti-Venomous Sera, by Captain G. Lamb, I.M.S. Price As. 3
or 4d.
No. 6. First Report on the Anti-Malarial Operations in Mian Mir, 1901—03, by Captain
S. P. J ames, I.M.S. Price As. 12 or 1s. 2d.
No. 7. Some Observations on the Poison of the Banded Krait (Bungarus Fasciatus), by
Captain G. Lamb, I.M.S. Price As. 8 or 9 d.
No. 8. A Preliminary Report on a Parasite found in Patients suffering from Enlargement
of the Spleen in India, by Lieutenant S. R. Christophers, I.M.S. Price
Re. 1-8 or 2s . 3d.
No. 9. Second Report of the Anti-Malarial Operations at Mian Mir, 1901—03, by
Lieutenant S. R. Christophers, I.M.S. Price As. 10 or 1s .
No. to. Specificity of Anti-Venomous Sera (Second Communication), by Captain G.
Lamb, I.M.S.
Price As. 8 or 9 d.
No. 11. On a Parasite found in persons suffering from Enlargement of the Spleen in
India—Second Report, by Lieutenant S. R. Christophers, I.M.S. Price
Rs. 2. or 3s .
No. 12. On the Morphology, Teratology, and Diclinism of the Flowers of Cannabis, by
Major D. Prain, I.M.S. Price As. 14 or 1s. 4d.
No. 13. Oriental or Delhi Sore, by Captain S. P. J ames, I.M.S. Price As. 10 or 1s.
No. 14. On a Parasite found in the White Corpuscles of the Blood of Dogs, by Captain
S. P. J ames, I.M.S. Price As. 10 or 1s .
No. 15. On a Parasite found in persons suffering from Enlargement of the Spleen in
India—Third Report, by Lieutenant S. R. Christophers, I.M.S. Price As. 10
or 1s .
No. 16. The Specificity of Anti-Venomous Sera with special reference to a Serum prepared
with the Venom of the Daboia Russellii, by Captain G. Lamb, I.M.S. Price
As. 6 or 7 d.
No. 17. Snake-Venoms in relation to Hæmolysis, by Captain G. Lamb, I.M.S. Price
As. 6 or 7 d.
No. 18. Hæmogregarina Gerbilli, by Lieutenant S. R. Christophers, M.B., I.M.S. Price
As. 10 or 1s.
No. 19. On Kala Azar, Malaria and Malarial Cachexia, by Captain S. P. J ames, M.B.,
I .M.S. Price Re. 1-4 or 1s. 11d.
2
No. 20. Serum-Therapy of Plague in India ; Reports by Mr. W. M. Haffkine, C.I.E.,
and various Officers of the Plague Research Laboratory, Bombay, by Lieute
-
nant-Colonel W. B. Bannerman, M. D., B.Sc., F.R.C.S. I.M.S. Price As. 14
or 1s . 4d,
No. 21. On the Standardisation of Anti-Typhoid Vaccine, by Captain George Lamb,
M.D., I.M.S. (Director, Pasteur Institute of India), and Captain W. B. C.
Forster, M.B., D.P.H., I.M.S. Price As. 6. or 7 d.
No. 22. Mediterranean Fever in India : Isolation of the Micrococcus Melitensis, by Captain
George Lamb, M.D., I.M.S., and Assistant Surgeon M. Kesava Pai, MB.,
C.M., (Madras). Price As. 10 or 1s.
No. 23. The Anatomy and Histology of Ticks, by Captain S. R. Christophers,
I.M.S. M.B. Price Rs. 3 or 4s. 6d.
No. 24. On a Parasite found in the White Corpuscles of the blood of Palm Squirrels, by
Captain W. S. Patton, M.B., I.M.S. Price As. 12 or 1s. 2 d.
No. 25. On the importance of Larval Characters in the Classification of Mosquitoes, by
Captain S. R. Christophers, M.B., I.M.S. Price As. 8 or 9 d.
No. 26. Leucocytozoon Canis, by Captain S. R. Christophers, M.B., I.M.S. Price
As. 12 or 1s. 2 d.
No. 27. Preliminary Report on the Development of the Leishman-Donovan Body in the
Bed Bug, by Captain W. S. Patton, M. B., I.M.S. Price As. 8 or 9 d.
No. 28. The Sexual Cycle of Leucocytozoon Canis in the Tick, by Captain S. R.
Christophers, M.B., I.M.S. Price As. 12 or as. 2 d.
No. 29. Piroplasma Canis and its Cycle in the Tick, by Captain S. R. Christophers,
I.M.S. M.B., Price Rs. 2 or 3s ,
No. 30. The Theory and Practice of Anti-Rabic Immunisation, by Captain W. F. Harvey,
M. B., I.M.S., and Captain Anderson McKendrick, M.B., I.M.S. Price
As. 12 or 1s. 2 d .
No. 31. The Development of the Leishman-Donovan Parasite in Cimex Rotundatus-
Second Report, by Captain W.S. Patton, M.B., I.M.S., Price Re. 1 or 1s .
6 d .
No. 32. An Enquiry on Enteric Fever in India carried out at the Central Research
Institute, Kasauli, under the direction cf Lieutenant-Colonel D. Semple, M.D.,
and Captain E. D. W. Greig, M.D. Price Re. 1 -2 or 1s. 9d.
No. 33. The Production of Alkali in Liquid Media by the Bacillus Pestis, by Lieutenant-
Colonel W. B. Bannerman, M.D., B. Sc., I.M.S. Price As. 5 or 6 d.
No. 34. Standards of the Constituents of the Urine and Blood and the bearing of the
Metabolism of Bengalis on the Problems of Nutrition, by Captain D. McCay,
M.B., I.M.S. Price As. 12 or 1s. 2 d.
No. 35. Black-water Fever, by Captain S. R. Christophers, M.B., I.M.S., and Dr. C. A.
Bentley.
No. 36. Observations on Rabies : with special reference to an Atrophic form of the disease
occurring in animals, by Major G. Lamb, M.D., I.M.S., and Captain A. G.
McKendrick, M.B., I.M.S. Price As. 8 or 9d.
No. 37. Investigations on Bengal Jail Dietaries with some Observations on the influence of
Dietary on the Physical Development and Well-being of the People of Bengal.
by Captain D. McCay, M.B., B.Ch., B.A.O., I.M.S. Price As. 8 or 9d.
Published by and on sale at the Office of the Superintendent of Government Printing, India, Calcutta.
Copies are also available from all Agents for the sale of Government publications.
PRELIMINARY REPORT ON THE KILLING OF RATS
AND RAT FLEAS BY HYDROCYANIC ACID GAS.
AT the suggestion of Captain W. Glen Liston, I.M.S., experiments with
hydrocyanic acid gas, as a measure to exterminate rats and fleas,
were commenced in May 1909. The first experiments were made under his
supervision.
We were later informed by Mr. Lefroy, the Imperial Entomologist, that
large use had been made of this gas by the Agricultural Departments in the
United States of America and in South Africa. He kindly sent us some of the
literature on the subject along with an account of his own experiments conducted
at Pusa, all of which have proved of great help to us.
It will be useful to consider briefly some of the previous work done on this
subject. Hydrocyanic acid gas was first used in 1886 by Coquillet in California
to destroy the " Cottony Cushion Scale" insect on plants ; and later, fumigation
of nursery stock with this gas has become compulsory throughout certain of the
States. It is now used throughout Canada, the United States of America, South
Africa, and Australia, not only for the disinfection of nursery stock, but also as a
means of ridding orchard trees of their pests. More important for our purpose is
the use of the gas for the disinfection of houses, jails, and railway coaches. The
application has naturally been very limited on account of the deadly nature of the
gas. Most of the information on this point we have obtained from the Reports
of the Government Entomologist to the Cape of Good Hope for the years 1898
to 1901. In 1898 he considered the gas too dangerous for house disinfection;
but in 1900, at the request of the Colonial Office, he rid the Worcester jail of
the bed bug—"Acanthia lectularia"—by fumigation with hydrocyanic acid gas.
A year afterwards the buildings were still free from the pest. In 1901 he further
treated two more jails—Tokai and Kimberley—without any accident, although in
the latter jail so great a quantity of potassium cyanide was used as 271 lbs. At
the time the experiment was completely successful, although a year afterwards
the buildings were re-infested. He also notes in 1901 that the "use of the gas
for the destruction of vermin in sleeping carriages of the Cape Government
railways has now been practised for three years with perfectly satisfactory results
and without any accident."
There is also an interesting note to the effect that Professor W. J. Simpson
thought this gas might be utilised to cleanse premises in which cases of plague
had occurred, and experiments were actually undertaken to determine what mini-
mum strength of the gas might be necessary to destroy bed bugs, which at that
time were considered to be possibly the carriers of the plague germ. The
experiments were discontinued owing to the decline of the epidemic and the
departure of Professor Simpson.
In America also fumigation by this gas has been occasionally used to rid
buildings of pests. For example, in the "Proceedings of the 17th Annual Meeting
of the Association of Economic Entomologists of America" a paper was read
on the fumigation of a four-storey building to get rid of the " Clinocoris
lectularia." The building was of about 150,000 cubic feet capacity ; 80 lbs. of
potassium cyanide were used ; the building was kept shut up for two days. All
the insects and eggs were killed. " No eggs appeared to hatch afterwards
though examination was made frequently for a period of several weeks."
The chemicals
used—
(1) KCN
The production of the gas.
In all the work done the gas has been produced by the action of sulphuric
acid on potassium cyanide. These chemicals must be of a certain standard of
purity to get satisfactory results. With regard to the potassium cyanide, elabor-
ate investigations were carried out, chiefly by Everhart of the Southern College of
Pharmacy in the United States of America. His results are detailed by Wilmon
Newell in Bulletin No. 15 of the Georgia State Board of Entomology. They
generally are that failure to obtain satisfactory results in fumigation has in many
cases been due to the use of impure and adulterated cyanide which is often
represented and sold as being pure. Of the adulterants sodium chloride is the
most important as it produces loss and decomposition of the hydrocyanic acid
gas evolved.
Nitrates are another harmful adulterant. The most common adulterant in
low grade cyanides being sodium chloride, increased amounts of low grade
cyanides cannot be safely substituted for pure cyanide, though they are much
cheaper.
A high percentage of potassium cyanide in a sample is not sufficient unless
analysis shows the absence of chlorides and nitrates.
Of several different cyanides examined by Everhart, only two, those of
Merck & Co. (98—100 per cent.) and of the Baker and Adamson Chemical Co.
(99 per cent.) were found to meet all requirements.
In almost all of the experiments detailed in our tables, carried out before we
had read Newell's paper, we used 98 per cent. potassium cyanide or Burgoyne
Burbidges' potassium cyanide 100 per cent. (double salt). Captain Higham,
I.M.S., Assistant to the Chemical Analyser for the Government of Bombay,
kindly gave us an analysis of Burgoyne Burbidges' salt. It proved to be a
3
mixture of both potassium and sodium cyanides, yielding 33.9 per cent. hydro-
cyanic acid equivalent to 81.6725 potassium cyanide.
One hundred per cent. potassium cyanide would yield 41.5 per cent. of its
weight of hydrocyanic acid and 100 per cent. sodium cyanide 55.1 per cent.
There were no nitrates; but chlorides were present to the amount 3.778 per cent
calculated as hydrochloric acid.
The sulphuric acid ought to be commercial concentrated sulphuric acid
(specific gravity 1.83).
The proportional amounts of potassium cyanide, sulphuric acid, and water
are important. Coquillet in 1889 found that the best results were obtained by
u s i n g 1 p a r t p o t a s s i u m c y a n i d e , 1 p a r t o f s u l p h u r i c a c i d , a n d 2 o f w a t e r . B u t
the usage of different workers has varied considerably on this point. However,
the majority advocate the 1-2-4. formula, i.e., 1o z . o f 9 8 p e r c e n t . p o t a s s i u m
cyanide, 2 fluid ozs. of sulphuric acid, and 4 fluid ozs. of water. The advantage
is twofold: (1) There is enough water to dissolve the potassium bisulphate
formed and so prevent the deposit of this salt round the potassium cyanide which
would reduce the formation of hydrocyanic acid gas. (2) When 2 ozs. of
sulphuric acid at 20°C. were mixed with 4 ozs. of water at 20°C. the initial tem-
perature became 110°C. ; one oz. of potassium cyanide was added and the whole
mixture exposed to the outside air having a temperature of 14°C. for 40 minutes.
At the end of that period the mixture had a temperature of 32°C. The boiling
point of prussic acid is 26½°C., so that throughout the whole period the tempera-
ture was sufficient to volatilize the prussic acid.
If more water is added the initial temperature is less ; if less water is added
than 4 ozs. the addition of 1 oz. of potassium cyanide would also diminish the
initial temperature.
These conclusions were arrived at by Wilmon Newell, as noted in the above-
mentioned paper. Some experiments were performed on this point by us.
The room temperature was 28°C.
The initial temperature of both the sulphuric acid and the water was 28°C.,
quite sufficient for the volatilization of the gas.
I. Three parts of water were added to one part of sulphuric acid.
The initial temperature became 88°C.; after forty minutes the temperature
was 43°C.
II. Two parts of water were added to one part of sulphuric acid.
The initial temperature became 105°C.; forty minutes later the temperature
was 39°C.
III. One part of water to one part acid.
The initial temperature was 115°C.; forty minutes later the temperature
was 41°C.
(2) Sulphuric
Acid.
B 2
4
The end results vary then, not only with the initial temperature developed,
but with the bulk of fluid used. In cold climates, as in the Punjab in the Cold
weather, it would be advisable to mix the various chemicals in one large vessel
rather than distribute them in small charges about a room, as cooling of the
mixture in the latter case would occur so much more quickly.
Considering every point the use of the 1-2-4 formula is probably the best.
A few minor points advocated by various authorities are:—(I) The use of
fairly large lumps of potassium cyanide instead of powdering it. The generation
of the gas is too, violent with powdered potassium cyanide. Further the
powdered salt is apt to deteriorate on standing by exposure to air; and, lastly,
there is the increased cost of powdering the salt. If there is a sufficient excess
of sulphuric acid and water the inter-action of the chemicals is rapid—almost as
rapid with large pieces of potassium cyanide as with small. (F. A. Sirrine, New
York Agricultural Department, 1909.)
The Entomologist of the Cape of Good Hope advocates the use of lumps of
potassium cyanide, the size of an egg for one lb. charges and lumps the size
of an acorn for small charges.
(2) The acid ought to be poured into the water if splattering of the acid
is to be avoided. The potassium cyanide ought to be added last. The
maximum effect of the gas is then produced.
(3) The storage of the potassium cyanide is of importance as under
exposure to air and moisture it deteriorates rapidly. After a case containing
potassium cyanide has been opened means ought to be taken to prevent ingress
of ai r and moi st ur e. I t ought t o be kept i n a cool dr y pl ace. The same
precautions are necessary to keep the sulphuric acid from absorbing moisture.
Methods of carrying out Fumigation recommended by previous
workers.
(I) The quantity of potassium cyanide to be used per cubic space to be
fumigated.
There is some difference of opinion with respect to this point.
Burgess of Ohio in a paper on "Fumigation of Nursery Stock" states:
"A series of experiments in treating peach buds made in August 1902 showed
that s/4 o z . o f c y a n i d e t o e a c h 1 0 0 c u b i c f e e t o f s p a c e f o r 4 0 m i n u t e s ' e x p o s u r e
killed all San Fose scales and no injury resulted to buds."
Newell of the Georgia State recommends 1 oz. of 98 per cent. potassium
cyanide to 100 cubic feet. With this dosage he states that "trees heavily
infested with the San Jose scales and protected with a heavy layer of earth failed
to show any live scale insects within a year of being fumigated."
5
Sirrine advises 25 grammes of potassium cyanide per too cubic feet ; or
for orchard trees, owing to the moisture and absorption of the evolved hydro-
cyanic acid gas, 30 grammes, i.e . , about 1 oz. t o 100 cubi c f eet .
The Government Entomologist for the Cape of Good Hope in his Report
for the year 1901 states that bugs are more refractory to the gas than any other
house insect. One ounce of potassuim cyanide to 155 cubic feet of air space
with an exposure of one hour killed 12 out of 15 bugs. The remaining 3 were
very feeble. Eggs of the bugs failed to hatch in three tests after exposure for
one hour to gas of the above strength.
He advises the use of one ounce to too cubic feet of space and an
exposure for two hours. "When there are any deep cracks or crevices in any
building to be penetrated, one ounce to 65 cubic feet of space may be used."
(2) Actual procedure to be adopted as advised in the report of the Government
Entomologist for the Cape of Good Hope for the year 1901.
The building to be fumigated is made as air-tight as possible. Arrange-
ments should be made for opening doors and windows from the outside to.
ventilate after fumigation. Each room should be fumigated separately, if
possible, but sometimes two connecting spaces may be treated as one. In
the latter case crevices and splits in doors connecting the two spaces should be
enlarged and burrows opened up. Bedding, clothing, etc., should be spread out
to let the gas get full effect on them.
The vessels in which the chemicals are to be mixed must be of such a
nature that they are not acted on by them. Their size depends on the quantity
of chemicals to be used. They must be of such a shape that the depth of
combined sulphuric acid and water will cover the cyanide put in. They may be
glazed earthenware vessels or china washhand vessels. Lead vessels are good
but heavy and soft. Enamelware till cracked acts well. Kerosine oil tins will
serve for two or three different charges. One of these tins can take a charge of
3 lbs. of potassium cyanide—the utmost that ought to be put into one vessel.
Place the vessel near the middle of the room. Measure out quantities of water,
acid, and potassium cyanide. The man who measures out the potassium cyanide
ought to handle it with rubber gloves as the salt is so poisonous. Mix the acid
into the water, at once drop in the potassium cyanide at arm's length, and run out
of the room. Many people wrap up the potassium cyanide in soft paper which
takes a few seconds to be eaten through, permitting the operator to get out of the
room before the gas is given off. The American fumigators usually lower the
potassium cyanide by means of a string and pulley from the outside after the
door of the room to be fumigated is locked. As the hydrocyanic acid gas rises,