ON THE TOXICITY OF THE VENOM OF THE MEXICAN (DURANGO) SCORPION AS COMPARED WITH THAT OF THE CHINESE SCORPION

1. The amount of extractive substance contained in the poisonous glands of different species of scorpion and of the alcohol insoluble toxic matter of the extract appears to differ in different species; Mexican sting containing more extractive substance and alcohol insoluble toxic matter than the Chinese. 2. The active principle of the extract from scorpion glands seems to be of proteid nature. 3. The active principle of the extract is soluble in saline solution and less soluble in pure water, but insoluble in absolute alcohol and ether. 4. The active principle of the Mexican extract is affected very little by drying for a long time, but the extract when preserved in room temperature exposed to sunlight undergoes putrefaction and loses its convulsant character. 5. The active principle of the Mexican extract is not affected by heating to 100° C. for a short period, but is destroyed if the heating is continued for thirty minutes. 6. The activity of the extract is not destroyed by the prolonged action of alcohol, but is affected by the action of acid and alkalies, and alkalies act more destructively. 7. The active principle of the Chinese extract, when muscular twitching is taken as an indicator, is more resistant to treatment by chemical and physical agents. 8. The minimum fatal dose of the venom for mice is approximately 0.015 mgm. per gram body weight in case of the Mexican scorpion and 1.5 mgm. in the Chinese one; and for frogs, 0.01 to 0.05 mgm. in the former and 0.3 to 1.0 mgm. in the latter. 9. The symptoms produced by the extracts of Mexican and Chinese scorpion venom seem to differ in certain points: in the former the symptoms consisting of spasms and twitchings, reflex irritability, convulsions and paresis in frogs; and epileptic convulsions, profuse salivation and respiratory paralysis in mice, but in the latter convulsions are not noted in either kinds of animals. 10. The spasm and twitching are of peripheral origin and are due to the direct action of the poison upon motor nerve endings and the convulsions are produced by the action of the extract upon spinal cord and nerve endings. The last stage of paralysis is due to the depressive action on the motor nerve endings and the central nervous system. 11. Death in mice and guinea-pigs seems mainly to be due to suffocation which may be considered to be caused by the convulsions and paralysis of the respiratory apparatus and in frogs to the central and peripheral paralysis. 12. The extract raises blood pressure acting upon the motor apparatus of the heart. The isolated frog's and cat's hearts are affected by the dilute extract by stimulation, and by the strong extract first by a stimulation, then by depression. 13. The extract increases the tonus and rhythmic movements of smooth muscles. 14. The extracts have a haemolytic action upon both nucleated and non-nucleated blood corpuscles. In conclusion, I wish to express my sincerest thanks to Prof. John J. Abel for the valued material afforded me in carrying out the work and for constant advice, and also to Dr. David I. Macht and Dr. Charles A. Rouiller for their kind advice throughout the experiments.