EFFECTS OF VARIOUS PHYSICAL AND CHEMICAL AGENTS 97 



In their fundamental work Mitchell and Reichert made the following 

 observations : 



The effects of alcohol : When alcohol is added to fresh venom or to an 

 aqueous solution of venom a copious white precipitate occurs. The precipi- 

 tate washed repeatedly with further volume of alcohol was fatal when dis- 

 solved in distilled water (after drying) and then injected into pigeons. The 

 local effect was always very slight. The filtrate had no marked poisonous 

 effect. A more prolonged treatment (3 days) of the venom with alcohol 

 made the precipitate less soluble in water, but the clear soluble portion was 

 quite toxic. The insoluble particles were easily soluble in dilute acetic acid, 

 and the solution was fatal to pigeons. There was absolutely no local effect 

 and there was no suffusion of blood in the tissue as in the previous experiment. 

 In a pigeon injected with a nitrate (containing much of insoluble fine pre- 

 cipitates) clarified with NaCl crystals there was intense local effect in the 

 blackening and infiltration of fluid blood. The destructive effect of an acid 

 on the locally active principles of the venom (Crotalus adamanteus) was 

 mentioned. In another series of experiments Mitchell and Reichert found 

 that if there is enough water in alcohol the filtrate carries off a certain amount 

 of the active substances of cobra venom and the injection of the filtrate can 

 cause death. The filtrate became turbid on boiling and gave a decided pre- 

 cipitate with nitric acid. 



Dried venom when placed in absolute alcohol for a long time (3 months) 

 does not lose its activity and the alcohol does not dissolve out any of its poison- 

 ous constituents. 



The effect of caustic alkalies : Mitchell and Reichert examined the action 

 of potassic hydrate upon the venoms 'of Crotalus adamanteus, Crotalus horri- 

 dus, and cobra, and found that the equal weight of this salt rendered the 

 crotalus venom inert, but a much stronger potassic hydrate was required to 

 destroy cobra venom. Very interesting experiments were made as to the 

 relation between the loss of toxicity and coagulation of proteins by heat. 

 They found that coagulation is prevented by dissolving the venom in a sub- 

 destructive amount of the alkali before subjecting the venom to the action of 

 heat. This alkalization of venom did not protect the venom from the inac- 

 tivating action of heat, although no coagulation occurred. The effect of 

 sodic hydrate is the same as the potassic salt. The neutralization of the 

 alkalies brings back the toxic properties of the alkalized venom, although 

 not the original strength. 



The effects of ammonia : If used in a sufficiently large quantity some perma- 

 nent modifications of toxicity occurred, but the effect was not so marked as by 

 the use of potassic or sodic hydrates (Crotalus adamanteus venom being used). 



Potassic carbonate : This did not exert any decided effects upon the venom 

 of Crotalus adamanteus. 



Nitric acid: The precipitate produced by adding nitric acid to the solu- 

 tion of Crotalus adamanteus venom was found to be inert. The filtrate was 

 also inactive. Thus nitric acid destroys the crotalus venom. 



