J 1907.] Influence of Increased Barometric Pressure on Man. 19 
grammes), two (107, 87 grammes) survived. All the mice survived (18, 18, 
12, 10, 11, 10 grammes). 
24.1.07.—Fifteen mice and five half-grown rats were exposed to + 115 lbs. 
for two hours, and decompressed in five seconds. Three rats and 15 mice 
were unaffected. One rat was dead (froth in heart and veins), one 
paraplegic. 
In all our experiments on rats and mice, we find :—: 
| 
. . Percentage 
Died. Survived. mortality. cna 
IEpeuCS oR ser y Bees 0 6 10 . 37 548-16 54816 | 
Wiee so. .2. ec: 3 27 10 +3°69 
a, ee | 
Difference ......... —_ = 27 :5+8°96 | 
| 
The evidence in favour of the view that mice can stand rapid decom- 
pression better than rats is reasonably strong. Here body weight is 
apparently more important than age, full-grown mice being better subjects 
than young rats. 
Rats and Kittens. 
22.5.07.—Two full-grown rats (11 and 12$ ozs.), and three young kittens 
(11, 11, 10 ozs.) were exposed to + 120 lbs. for 55 minutes. Decompression 
time, 54 seconds. One rat was dead on removal; two kittens and the other 
rat died in a few minutes; one kitten survived. P.M.: The air emboli 
usually observed were present in all three animals. 
This experiment shows little advantage on the side of the young animals. 
The results we have described may be compared with the observations 
of earlier workers which we have collected and tabulated. These seem 
to show a relative immunity of the smaller animals to rapid decompression, 
and a death rate of almost 100 per cent. in the case of cats and dogs at 
pressures above six to seven atmuspheres. 
