INFLUENCE OF VARIOUS STAINS UPON VENOM. 



By Lucius Tuttle. 



In the following experiments we have determined the influence of heat 

 upon venom, both before and after the addition of certain stains. We have 

 tested the influence of these stains upon the toxicity as well as upon the pro- 

 duction of precipitates. In further experiments we have tested the influence 

 of light upon venom mixed with various stains, comparing these specimens 

 with similar ones which had been left in darkness. 



INFLUENCE OF STAINS AND HEAT UPON VENOM. 



In most of these experiments we useil a 0.5 per cent solution of eosin 

 (G. Griibler, water-soluble) made up with 0.85 per cent sodium-chloride solu- 

 tion, but in a few cases we used a 0.5 per cent solution of neutral red made 

 up with the same diluent. In experiments testing the toxicity of the various 

 solutions we injected quantities of the various mixtures into mice, in one exper- 

 iment onlj' (an experiment in which eosin was used) we used rats to test the 

 toxicity of the venom. In all cases we heated the venom for 10 minutes to 

 a temperature of 100° C. 



We found that when 0.15 c.c. of the 0.5 per cent eosin solution was added 

 to 0.85 c.c. of diluted venom (0.5 c.c. of venom diluted with twice its volume of 

 0.85 per cent NaCl solution plus 0.35 c.c. of NaCI solution) no precipitate 

 appeared, but if only 0.1 c.c. of the eosin solution was added to 0.9 c.c. diluted 

 venom (0.5 c.c. of diluted venom and 0.4 c.c. NaCl solution) a precipitate 

 appeared after boiling for 10 minutes. We furthermore noted that when suffi- 

 ciently large quantities of 0.5 per cent eosin solution were added to fresh undi- 

 luted, unfiltered venom, which as usual was turbid, it was possible to diminish 

 but not to prevent altogether the precipitate . Even though we added a quan- 

 tit.y of solid eosin more than sufficient to saturate the undiluted unfiltered 

 venom (the solid eosin being dissolved on heating) we were unable to prevent 

 precipitates in this turbid venom. Aron found previously that addition of 

 eosin to a proteid solution prevented the formation of precipitates.* 



With the neutral red we were unable to prevent precipitation even when 

 0.3 c.c. was added to 0.7 c.c. of diluted venom (0.5 c.c. of venom diluted with 

 twice its volume of 0.85 per cent NaCl solution and 0.2 c.c. NaCl solution). 



We tested the influence of eosin and heat combined upon the venom in five 

 exi^eriments. In each series we injected several mice with different quantities 

 of venom which had been heated, venom mixed with eosin and heated, and 



*Aron. Biochemische Zeitschriit, 1907, v, 413. 



207 



