PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 247 
same symptoms of gradual extinction of function of the nervous 
system as those inoculated with the unheated venom. When the 
animals were completely paralysed, the heart was found to be still 
beating fairly strongly. 
To test the effect of venom on the reflex activity of the cord, 
Ture’s method was employed. The brains of seven frogs were 
destroyed, and the animals were then hung up in a row by the 
lower jaw. About every five minutes the foot of each frog was 
dipped in a -4% solution of sulphuric acid. The moment the foot 
touched the fluid a chronograph was started, and the moment 
there was any movement of the leg, it was stopped. The 
chronograph measured to one-fifth of a second. 
The time intervening between the commencement of the 
stimulation and the beginning of response, (latent period of 
response ), was then noted, and the foot of the frog washed in a 
beaker of water. The whole process was then repeated with the 
next frog. Ags the activity of the cord diminished, the latent 
Period increased. When the seven frogs had been tested three 
times in this way, ‘01 gramme of venom dissolved in °5 ce. salt 
solution, and previously heated to 85° C., was injected into the 
dorsal lymph sac of three of them, and the hearts of two were 
cut out, while the remaining two served as controls. The effect 
of the poison, and also the effect of cessation of all circulation 
upon the latent period of response is shown in the following 
table, where the columns of figures represent this latent period of 
response in seconds. 
et: rk: Frog 2 Frog 3 Frog 4 Frog 5 Treg 7 | Frog 7 
Seconds | S ds. | 8 ds. | Seconds, | S ds. | Seconds. | Seconds. 
Se" 26 | is |" 26 | 20 | 20 | 16 bee 
ob “1 +e 2°2 2-4. 13 ~~ 1-4 16 
10 ,,/} © 28 26 Be 1:2 ‘8 1:8 
es ag ee heartcuti/heartcut|'01 gramme heated venom 
t u injected into lymph-sac. 
: : P 
bi a 6 30 28 1-0 1:4 1:0 18 
3-30 it he 28 2-4 1-0 1-2 18 22 
eo... © 22 26 1-2 46 3-4 40 
349 ” 6 22 4:0 ~ |no response} 5 no respons? 
345 8 3-0 10 response = no response ” 
= 30 ee 10 response a ” a 
Next day 3-4 4-9 oT or s : wee 
