84 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



Alhumose and Syntonin : Slow-diffusible proteins are still found in the fil- 

 trate of the venom solution heated to 95° C. Wolfenden beheves that they 

 belong either to acid albumin or albumoses, but not to peptone, because 

 they can be removed by ferric acetate. This author expresses the opinion 

 that the substances called peptones by Mitchell and Reichert belong to albu- 

 moses. 



In 1892 Kanthack ^ made a thorough examination of the venom of Naja 

 tripudians atrox. He brought out evidences that the chief active principle 

 of cobra venom is albumose ; and he gives the following summing up : 



(a) The fresh protein precipitate, whether obtained by the addition of absolute 

 alcohol or ammonium sulphate, is amorphous and white, but when dried slowly 

 it forms a translucent colorless mass. 



(b) Its solution is colorless or slightly opalescent, and neutral or alkaline to 

 litmus paper. 



(c) It is very soluble in water, quite insoluble in alcohol. 



(d) It gives a brilliant biuret reaction with caustic potash and a trace of cupric 

 sulphate. 



(e) Nitric acid gives a precipitate, soluble on heating and coming down on cool- 

 ing if the solution is of sufficient concentration. With dilute solution a trace of 

 sodium chloride must be added to cause precipitation. 



(0 Picric acid causes a precipitate, dissolved on heating, but appearing or form- 

 ing again on cooling. 



(g) Boiling produces no physical changes. 



(h) Saturation with ammonium sulphate gives a precipitate. Letting the fluid 

 stand for 48 hours and filtering off the precipitate, the clear filtrate gives no biuret 

 reaction, while a solution of the white precipitate reacts beautifully. On adding 

 acetic acid to the filtrate no precipitate is obtained. 



(i) Saturation with sodium chloride causes a precipitate. The filtrate gives 

 no biuret reaction, nor a precipitate on the addition of acetic or nitric acid. 



(f) The solution gives the ordinary protein reactions, the color with Millon's 

 reagent being less bright, and more of a pinkish-yellowish hue. 



From these reactions Kanthack concludes that the substance in question 

 is an albumose, and that only one, a primary albumose, is present. The 

 presence of an alkaloid is denied. 



According to Kanthack, cobra venom does not contain any appreciable 

 amount of globulin. The substance described by Weir Mitchell and Reichert 

 as globulin is, according to this author, certain derivatives of the proto- 

 albumose of the same venom. 



> A. A. Kanthack. The nature of cobra poison. Jour, of Physiology, 1892, XIII, 272. 



In 1892 Martin published a method for separating the albumoses from snake venom. It is as 

 follows: The poison is slightly diluted with sterilized water, and then thrown into a large 

 excess of alcohol, and allowed to stand for a week. The alcohol is separated ofi and the 

 white precipitate washed with absolute alcohol, dissolved in sterilized distilled water, and once 

 more precipitated by alcohol. The resulting precipitate is allowed to stand underalcohol for 

 a week, then washed with alcohol and dissolved in water, to which a little thymol is added to 

 prevent putrefaction. The solution is found to contain no other proteins than albumose. 



Hawkins' method for separating albumose employed by Wolfenden. The solution of cobra venom is 

 saturated with ammonium sulphate and the mixture allowed to stand for several days. The 

 white precipitate is dissolved in water and dialyzed until all trace of the salt has disappeared. 

 The solution is then concentrated by dialysis against absolute alcohol, and subsequently poured 

 into a large excess of alcohol and treated as in Martin's method. (Brit. Med. Journ., 1890, 

 July 12.) 



