L.^BORATORY EXPERIMENTS. 7 



LABORATORY EXPERIMENTS WITH DELPHINIUM CAMPORUM. 



Specimens of Delphinium camporum were sent from Fort Collins, 

 Colo., for testing in the lahonitory of Poisonous-Plant Invest i^jat ions. 

 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. 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 flgures. Of this aque- 

 ous solution 1 c. c. injected subcutaneously into a guinea pig weigh- 

 ing 730 grams caused no disturbance, and 3 c. c. were also Avithout 

 effect, whereas c. c. killed the same guinea pig in 55 minutes. A 

 solution of 4 c. c. injected into a guinea pig weighing 352 grams 

 caused no symptoms, while T) c. c. injected into another guinea pig 

 weiirhino; 285 grams killed in 33 minutes. Later, 5 c. c. killed a 

 guinea pig weighing 10() grams in 55 minutes, while 4 c. c. injected 

 into a guinea i)ig weighing 299 grams gave no symptoms. Evi- 

 dently the lethal dose of this solution lies between 4 and 5 c. c. The 

 solution used in the above experiments was made from plants col- 

 lected on April 20, 1905. i 

 On May 10 another lot of material was collected, and a solution 

 corresponding to 4 c. c. of the first batch was injected into a guinea 

 ])ig weighing 455 grams without producing any symptoms. However, 

 5.3 c. c. of this solution killed a guinea i)ig weighing 350 grams, but 

 a much longer period elai:>sed before death occurred than Avith the 

 extract of the first material. 



In June another lot of material was collected, and a solution of 

 this corresponding to 4 c. c. caused no symptoms in a guinea pig 

 weidiinff 376 grams: 5.3 c. c. caused no svmptoms 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 kill. 

 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 Delphinivin eonsolida is also less active 

 when mature.'^ 



Just after flow^ering, the purple larkspur turns yellow and ceases to 



" Dammaun, C. Gesuiulbeitspflege, 1880. p. 1072. 

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