HE LARKSPURS AS POISONOUS PLANTS. 
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LABORATORY EXPERIMENTS WITH DELPHINIUM CAMPORUM. 
Specimens of Delphinium camporum were sent from Fort Collins, 
Colo., for testing in the laboratory of Poisonous-Plant Investigations. 
Five grams of the dried and powdered plant were accurately weighed 
and then extracted over night with 20 ¢c. c. of water and 10 ¢. c. of 
95 per cent alcohol. The alcohol was added mainly as a preservative. 
The following day the extraction and squeezing were continued until 
the fluid became colorless. The fluid was evaporated on the next 
day in vacuo at about 40° C., and the residue was dissolved in water 
and made up to 30 c. c.—perfectly arbitrary figures. Of this aque- 
ous solution 1 ¢. c. infected subcutaneously into a guinea pig weigh- 
ing 730 grams caused no disturbance, and 8 ¢. c. were also without 
effect, whereas 6 c. c. killed the same guinea pig in 55 minutes. A 
solution of 4 ¢. ¢. injected into a guinea pig weighing 352 grams 
caused no symptoms, while 6 ¢. c. injected into another guinea pig 
weighing 285 grams killed in 33 minutes. Later, 5 c. c. killed a 
guinea pig weighing 196 grams in 55 minutes, while 4 c. c. injected 
into a guinea pig weighing 299 grams gave no symptoms. Ev1- 
dently the lethal dose of this solution lies between 4 and 5c. c. The 
solution used in the above experiments was made from plants col- 
lected on April 26, 1905. 
On May 16 another lot of material was collected, and a solution 
corresponding to 4 ¢. c. of the: first batch was injected into a guinea 
pig weighing 455 grams.without producing any symptoms. However. 
5.3 ¢c. c. of this solution killed a guinea pig weighing 350 grams, but 
a much longer period elapsed before death occurred than with the 
extract of the first material. ; 
In June another lot of material was collected, and a solution of 
this corresponding to 4 ¢. ce. caused no symptoms in a guinea pig 
weighing 376 grams; -5.3 c. c. caused no symptoms in a guinea pig 
weighing 500 grams, and 6.6 c. c. was inactive in a guinea pig weigh- 
ing 480 grams. Of the dried material 10 grams were then extracted, 
and killed a guinea pig weighing 320 grams only after about 10 
hours. A control amount of plain distilled water failed to lull. 
The lethal dose is evidently much higher than in the second stage. 
There is no question as to the fact that Delphinium when injected 
subcutaneously will kill, and these experiments also establish the fact 
that the plant loses much of its toxicity as it approaches the flowering 
stage. It has been noted that Delphinium consolida is also less active 
when mature.? 
Just after flowering, the purple larkspur turns yellow and ceases to 
aDammann, C. Gesundheitspfiege, 1886, p. 1072. 
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