i66 
Journal of Agricultural Research 
Vol. XXI. No.* 
hookworms and left 22, an efficacy of 42 per cent; it removed 43 asca- 
rids and left 22, an efficacy of 66 per cent; it removed no whipworms and 
left 95, an efficacy of o per cent. By comparing these results with the 
results attained in administering carbon tetrachlorid at the same rate in 
capsules, it is evident that the change in mode of administration has been 
followed by a sharp decrease in efficacy from 100 per cent against hook¬ 
worms and ascarids to 42 per cent against hookworms and 66 per cent 
against ascarids. We may conclude from this that the drug should be 
administered in capsules in order to develop its maximum effect. 
In the following experiment the dog was given a large dose of carbon 
tetrachlorid and not killed, in order to ascertain whether there were any 
symptoms of delayed poisoning. 
Dog 414; 1 in. p. k.; 1 hookworm first day; no post mortem and no 
conclusions as to efficacy. This dog was given 15 mils of castor oil and 
then 4 mils of carbon tetrachlorid, half of the entire dose of carbon tet¬ 
rachlorid (weight of dog, 8 kgm.), without capsules. The dog staggered 
and appeared to be in a spasm. Another 15-mil dose of castor oil was 
then given, and another 4-mil dose of carbon tetrachlorid was given in 
capsules. The dog went down and stiffened out for a short time, then 
arose and staggered about as if intoxicated for a few minutes. The 
animal soon became normal in behavior and appearance and at the end 
of over four months has shown no evidence of bad effects. The transient 
toxic effects are to be attributed to the inhalation of the drug when 
given in large amount without capsules. 
CARBON TETRACHLORID PLUS THYMOL 
In order to ascertain whether thymol, which is readily soluble in carbon 
tetrachlorid, could be added to carbon tetrachlorid with any increase in 
anthelmintic efficacy, a solution was made up at the rate of 1 mil of car¬ 
bon tetrachlorid to 10 gr. of thymol. This solution was administered in 
capsules in dose rate of 0.3 m. p. k. after fasting and without purgation 
as follows: 
Dog 416; 5 hookworms and some Dipylidium sp. chains first day, 
some Dipylidium sp. chains sixth day; p. m., no worms; 100 per cent vs. 
hookworms and Dipylidium sp. 
Dog 417; no worms in 4 days; p. m., 175 Dipylidium sp.; o per cent 
effective vs. Dipylidium sp. 
Dog 418; 55 hookworms first day, 6 hookworms second day; p. in., 22 
whipworms, 34 Dipylidium sp.; 100 per cent vs. hookworms, o per cent 
vs. whipworms and Dipylidium sp. 
In the foregoing experiments this mixture, in the proportion of 1 mil 
of carbon tetrachlorid to 10 gr. of thymol, given in capsules at the rate of 
0.3 m. p. k. to 3 dogs, removed 66 hookworms and left none, an efficacy 
of 100 per cent; it removed no whipworms and left 22, an efficacy of o 
