234 THE VENOM OF HELODERMA. 



hardened filter paper. A portion of the filtrate thus obtained was carefully 

 neutralized with sodium carbonate. The solution was almost colorless and 

 ^ave no trace of the biuret reaction. Of the neutralized solution 0.5 c.c. was 

 injected into a mouse of 20 gm. beneath the skin of the abdomen. The mouse 

 became restless; after half an hour, some dyspnea appeared with possibly some 

 weakness; but these passed away, so that on the following day the mouse was 

 quite well. As a dose of 0.5 c.c. produced so few effects, 3 hours later 1 .6 c.c. of 

 the same solution were injected into a fresh mouse of 22 gm. beneath the skin 

 of the abdomen. Such a relatively large amount of liquid always causes a great 

 ■deal of discomfort, but for some hours little else was noticeable. The injection 

 was made at 3 p. m. ; at 5 p. m. some paralysis and dyspnea began to appear; at 

 6 p. m. the mouse was weak and lay flat upon its abdomen as though paralyzed, 

 but it still reacted to pinching; at 6*" 46"" p. m. it no longer reacted to pinching, 

 but was still able to move about feebly. It was not again observed till the fol- 

 lowing morning, when it had apparently recovered. By the following evening 

 it was quite well and vigorous. 



It was thought that perhaps the failure of this method might be due to the 

 quality of the metaphosphoric acid used; therefore the entire experiment was 

 repeated with metaphosphoric acid prepared from phosphorus pentoxide, as 

 recommended by Abel and Ford.* This modification did not alter the result. 

 Evidently this method, which has been so successful in the hands of Faust and 

 ■of Abel and Ford, is not applicable to heloderma venom, because so much of the 

 toxic material is held in the precipitate produced by acetic acid and heat, while 

 almost all the remainder is carried down with the metaphosphoric acid pre- 

 cipitate. 



The next method tried was the precipitation of the protein with dialyzed 

 colloidal iron. A solution of 0.2 gm. venom in 15 c.c. of water was prepared as 

 before. On the addition of the colloidal iron a very heavy and abundant pre- 

 cipitate was formed. The addition of iron was continued until a precipitate no 

 longer resulted. The precipitate was removed by centrifugation. The clear 

 supernatant liquid did not give the biuret reaction and contained but a very 

 small amount of material in solution. 0.5 c.c. was injected into a mouse of 19 

 gm. beneath the skin of the abdomen at 1 1 a. m. All day the mouse showed no 

 symptoms except those due to the injection, and on the following morning was 

 quite well. A second mouse of 22 gm. received a similar injection of 1.5 c.c. at 

 2 p. m. This mouse showed moderate paralytic symptoms from 5 to 8 p. m.; 

 but on the following morning it had quite recovered. Evidently the toxic 

 material is carried down with the protein by the colloidal iron. 



The toxic principle seems to differ from that of the cobra and of the rattle- 

 ■snake in the greater ease with which it is adsorbed by all kinds of precipitates. 

 Thus a solution of 0.05 gm. venom in 5 c.c. of water was filtered from the insol- 

 uble portion and freed from coagulable protein. The solution obtained was 

 very toxic. It was then shaken with a little pure kaolin. The kaolin was 



•Abel, J. J., and Ford, VV. \V. On the poisons of Amanita phalloidea, Journal of Biological Chemistry, vol. ii, p. 278 

 (1907). 



