52 
cases belonged to the same lot, and the experiments were carried out 
at the same time. Protocols of the control experiments using anti- 
p}uine and of the experiments using a mixture of antipvrine and 
caffeine citrate are given in the tables which follow. 
Con tro I — a n tipyrine . 
[Detennination of the minimum lethal dose of antipyxine for guinea pigs. — Survuved; + death.] 
Weight 
in grams. 
Dose per 
gram. 
Result. 
Hours 
till 
death. 
1 46.5 
0. 0011 
1 415 
.0012 . 
' .345 
.0012 
395 
.0013 
: .380 
.0014 
-- 
7.30 
.365 
.0014 
U_ 
10.45 
4.35 
.0015 
— 
4.35 
.0015 
+ 
11. 45 
445 
.0016 ■ 
-j- 
12. 45 
470 
.0016 
-!- 
3.00 
A series of guinea pigs belonging to the same lot were given a mix- 
ture of antip}uine and caffeine in the determination of the least fatal 
dose, with results as follows : 
[Antipyrihe and caffeine mixture: Determination of the least fatal dose of a mixture of antipj*rine and 
caffeine citrate for guinea pigs, —survived; death.] 
Estimating the minimum lethal dose of antip^'rine for guinea pigs 
as 0.0014 gram per gram body weight, the experiments with a mixture 
of antipyrine and caffeine indicate an increased toxicity to the simple 
drug, the amount of antipyrine producing death in the mixture being 
0.0012 gram per gram body weight, or an increased toxicity in the 
inverse ratio of 12 to 14, 
