cex Proceedings of the Asiatic Society of Bengal. [N.S., XV, 
acid will give sreroneey.: id parts of HCN per 100,000 parts by 
volume a ruses gase 
Now 
s been jou = hat 30 parts of HCN per 100,000 parts of air 
=e a Bea acgch ill suffice to ee all stages of development including the 
eggs of bugs and lice provided an exposure of two hours is given at that 
concentration o ae that when a r is fill ith 
clothing the concentration of the gas very appreciably decreases; it 
rge rooms co: ing clothing are being 
treated, not only to convey gas to different parts of the room but 
also to Fe cipiontid xe eans estimating the strength of the gas acter 
within This has been effected by the arrangement t which i 
illustrated. 
a cubic foot of the air within the room is withdrawn by means 
of an eine ; the air, as itis drawn from the room, is passed through 
a weak solutio n of caustic soda. The solution very rapidly absorbs the 
gas contained in the sample and the concentrati H in the 
solutio; ted b ns of a standard silver nitrate solution 
y me 
using potassium iodide as an indicator. The igor silver nitrate 
solution is of rat a strength that 1 c.c.=10 parts of HCN per 100,000 
air when the quantity of air withdrawn is half a cubic foot. The 
standard s olen on is esr by di Guoltind 5114 grammes of silver nitrate 
in | litre of pi wa 
seri 
n oa gas 
for different periods on eggs, larval and imago stages of lice bugs 
and cockroaches. The pan of these experiments are recorded in the 
joi table. 
w 
S 
&. 
3 
5 
8 
experimental ae will be on view at set ae and 
is g the d 
and other vermin in beds, in clothing and in furniture. No tat: in 
India should be without one of these very a vermin-killing rooms. 
The method of ised 3 is very simple and can be used without danger if 
attention is paid to certain very elementary ace meen 
of eating 1,000 cubic feet of space ‘at pre-war rates 
n 
pplie mals as compared w 
relatively less susceptible thn poizonouss effects of rr gas. Birds are 
very easily kille 4 co oncentration the gas which are harmless for men. 
A sparrow may sed to indi sate: when a place containing the gas 1s 
safe to enter. "Tihalations of small quantities of gas fo i —— periods, e.g. 
when working with it does not cause toxic In this latter 
respect HCN has a great advantage over panei vl fermen poisonous gases. 
ve Bsns Vina of deficiency disease,—By R. McCaRRI- 
Co ee el Marrs recounts the results of his experiments on feed- 
ing pigeons on a diet consisting solely of polished rice; that is to say, on 
ess t 10% 
di pie of starch, with less than 10% of protein an 
complete aksence of a t One and sixty-eight 
f th veloped polyneuritis avium within the period of the ex- 
perim e heart’ he i f dr 
Th 
and inane two birds so fed were examined bacteriologically at autopsy ; 
of these ninety-four were found to have had concurrent septicemic infec- 
tions of various kinds, while the heart’s blood and organs of forty-eight 
were sterile. Four out of one hundred and forty-two had tubercular 
dineunts of the lungs or abdominal viscera, or both. 
