EFFECTS OF VAEIOUS PHYSICAL AND CHEMICAL AGENTS 101 



action of such precipitate is just as strong as the pure venom. Chloride of 

 sodium and sulphate of magnesium in saturation belong to the same group 

 in that respect. 



Hydrates of sodium and potash are destructive when used in strong con- 

 centration and allowed to act at least for several minutes, but not in dilute 

 condition. 



Peroxide of hydrogen, phosphoric acid, sulphuric acid, and hydrochloric acid 

 are inactive on venom in vitro. 



Carbonate of sodium or ammonium in i to lo does not bring about any 

 reduction of the toxicity of cobra venom when mixed in lOO parts of these 

 salts with I part of the venom. Phosphate and sulphate of ammonium form 

 a whitish albuminous precipitate, which is toxic. 



Hypersulphate of ammonium does not form precipitate with venom, 

 and the mixture of 20 parts of the salt with i part of the venom does 

 not kill, but this is found to be due partly to the interference of absorption 

 by the salt. 



Permanganate of potash (i to loo) : The solution of this salt when mixed 

 with venom in ratio of 10 to i previously to the injection stops the fatal effect 

 of the venom. Even if the venom is first injected intramuscularly and then 

 the solution of potash permanganate (i : loo) is immediately injected into 

 the same needle-track the animal never succumbs. But if a short space of 

 time should elapse before the injection of the permanganate solution, toxica- 

 tion takes its normal course. Neither is the effect of venom counteracted 

 in the organism if injected at different parts of the body. This point has 

 long been known from the work of Mitchell. 



Bromine water (saturated) and chlorine water were found to be quite 

 efficacious in destroying the venom in the tissue, even after venom has been 

 introduced for 10 minutes. It can be used in i : 3 dilution, without any 

 abscess or ulceration, but it is very painful. 



Hypobromide of sodium is inactive. 



Calmette found that calcium chloride or calcium hyperchlorite in solution 

 of I to 12, from which another dilution with 5 to 6 volumes of water is made, 

 at the moment of use, can be used to destroy the venom in the bitten locality. 

 Chloride of gold in i to 100 can be used for the same purpose. All these 

 chlorides and hypochlorites form with venom an insoluble and innocuous pre- 

 cipitate. Their action is, however, a direct one. 



Platinum chloride forms a soluble precipitate, and its destructive effect is 

 very slow. Picric acid forms a precipitate, disappearing on heating and 

 reappearing on cooling. 



Kaufmann (1889) found that chromic acid removes the toxic constituents 

 of viperine venom, by forming insoluble, innocuous precipitate. Calmette 

 confirms this observation by using i per cent solution, but adds that the 

 acid frequently produces necrosis of the tissue which comes in contact with 

 the acid. 



