12 BULLETIISr 405^ U. S. DEPARTMENT OF AGRICULTURE. 



of the heart, hence they are probably not muscular. Further, when 

 the heart is quickened by large doses, electric stimulation of the 

 vagus has but little effect. The drug may therefore be said first to 

 stimulate and then depress the vagus end mechanism. It may have 

 a similar action on the vagus center. 



Strength of the heart. — This is affected only by rather large doses, 

 but it is then always depressed. Experiment 87 shows that the hfe 

 may be kept up with a complete vasomotor paralysis, if the heart 

 beats well. This tends to show that the stoppage of the heart, which 

 forms the final cause of death, must be due to paralysis of its muscles. 

 This is confirmed by the fact that it can not be revived by injection 

 of normal sahne. 



Convulsions. — Convulsions were observed in but two of the five 

 cases. This may be due to the anaesthetic or to the difficulty of 

 securing proper dosage. When observed, however, they preceded 

 respiratory distress and were not connected with any change in 

 blood pressure, so that it seems that they are produced by a direct 

 central action. 



Slceletal muscle. — The existence of convulsions in the last stages, as 

 well as the result of stimulation of peripheral and of the sciatic, show 

 that muscle and nerve are not paralyzed. 



Cause of death. — The following vital functions are eventually 

 paralyzed by the lupine: Kespiratory center; vasomotor center; 

 cardiac muscle; the last named being the last to become paralyzed 

 and being the final cause of death. 



SUMMARY. 



The results of the investigations are in many respects incomplete 

 and emphasize the need of a more exhaustive chemical and pharma- 

 cological study of the American lupines. They have shown, how- 

 ever, that these lupines contain alkaloids which are toxic or fatal if a 

 sufficient quantity of the plant is consumed, but which are harmless 

 if the consumption is below a certain limit. Up to this point the 

 lupines may be a useful food if due precautions are observed that the 

 limits are not surpassed. These alkaloids could also be largely 

 removed by leaching with water. The ictrogen, which is especially 

 feared in Europe, was not found in any of the American samples. It 

 would be of great importance to determine whether this ictrogen is 

 uniformly absent, for if it is not, much more stringent precautions 

 would be necessary. 



CONCLUSIONS. 



1. Feeding with the lupines does not produce any symptoms in 

 rabbits and guinea pigs, as a sufficient quantity is not taken in this 

 iTianner. 



2. The injection of extracts, by stomach or skin, is fatal if suffi- 

 ciently large doses are used. 



