Larkspur and Othkr Poisonous Plants. iy 
The First Batch Collected April 26tli, 1905. 
Cau S ea C M °'disturb e ance. t0 a P ‘ S < subcutaneo « sl y). weight 730 grams. 
3 c. c. in guinea pig, no symptoms. 
6 c. c. in guinea. Killed. 
6 c. c. injected into guinea pig, 28 5 grams, killed in 3 3 minutes. 
4 c. c. injected into guinea pig, 352 grams, no symptoms 
Repeated: 
5 c. c. killed guinea pig weighing 19 6 grams. Died in 55 minutes. 
4 c. c. injected into guined pig, 299 grams. No symptoms. 
Evidently lethal dose for this solution lay between 4 to 5 c. c. 
Second Stage, Gathered May 16tli, 1905. 
Solution corresponding to 4 c. c. of No. 1 caused no symptoms in 
guinea pig weighing 445 grams, while 5.3 c.c. gilled one of 350 grams, but 
death was delayed longer than with extract of first stage. 
Third Stage, Gathered in June, 1905. 
Solution corresponding to 4 c. c. caused no symptoms in guinea pig 
weighing 376 grams. 
5.3 c. c. caused no symptoms in guinea pig weighing 500 grams. 
6.6 c. c. caused no symptoms in guinea pig weighing 480 grams. 
. Evidently lethal dose is much higher and the plant loses much of its 
activity in development. 
This report is very conclusive in proving that the plant con¬ 
tains an active poison, and further in substantiating the claims of 
experienced observers that the plant loses much of its toxic proper¬ 
ties as it approaches the flowering period. 
Correspondence with those who have had wide experience with 
larkspur elicits the fact that animals often eat considerable quan¬ 
tities of the plant without injury. Rabbis lived for days on a 
on a spare diet of dried purple larkspur, but succumbed readily to the 
more tempting bait of the green. 
It is not the purpose of this bulletin to give a detailed report 
of laboratory experiments. The results will be briefly summarized 
at the conclusion of this report. As proof, however, of the state¬ 
ments made regarding the difficulties of securing accurate knowl¬ 
edge of the toxic properties of plants under any and all conditions, 
the following experiment is interesting as well as instructive: 
Seven and one-half grams of dried purple larkspur fed to 
each of three rabbits on April 20th. No results. 
Seven and one-half grams of fresh purple larkspur from same 
patch fed April 25th to each of three rabbits. Two showed slight 
uneasiness, and one was bloated a little. One, showing less effect 
than the others, had eaten but three and one-half grams. 
On May 1st a like quantity from the same patch was given to 
the same rabbits under similar conditions. Results, two died, and 
the other distressed. 
O11 June 15th, the plants from the same source being in full 
bloom, but the leaves and stems dry, were fed to rabbits. Al- 
