10 THE VENOMS OF CERTAIN THANATOPHIDEiE. 



masses of granular matter with epithelial cells and salivary corpuscles, and a few- 

 flat crystals resembling cholesterin: 



The precipitate gives no proteid reactions with the usual proteid color tests, is 

 insoluble in neutral saline solutions, and in weak or strong acids or alkalies. Boil- 

 ing seems to render the mixture clearer. 



When injected into pigeons this precipitate does not appear to possess any toxic 

 properties. 



The Globulins.— If, after the separation of the above insoluble precipitate, the 

 venom be mixed with water and placed in a dialyser over running water it will be 

 found that within a few hours a whitish precipitate will occur within the dialyser, 

 and should dialysis be continued sufficiently long the precipitate will have become 

 deposited .in abundance. If the precipitate thus formed be collected on a filter it 

 will be found that all of the coagulable proteids have been thrown down, since the 

 filtrate now yields no coagulum by brief boiling, although it gives a proteid reaction. 



The precipitate is now washed from the filter and subjected to repeated wash- 

 ings and decantations with distilled water, until the wash-water gives no proteid 

 reaction. This purified precipitate is found to give reactions peculiar to the 

 globulins ; it is insoluble in distilled water, soluble in dilute neutral saline solu- 

 tions, soluble in dilute acids and alkalies, becomes turbid at about 60° C, and is 

 fully coagulated at a point a little above 70° C. 



The filtrate still contains some proteid in solution, since we find, by the usual 

 color and chemical tests, a proteid reaction, although it is observed that no coagu- 

 lation occurs by momentary boiling. The filtrate is not precipitated by strong or weak 

 mineral acids, by solutions of ferric chloride or cupric sulphate, it is precipitated but 

 not coagulated by absolute alcohol, and if placed in a dialyser it will be found to be 

 readily dialysable. These reactions it will be observed place the proteid which 

 remains in solution in the filtrate among the peptones. But we shall revert to this 

 hereafter. 



It will thus be clear that we have separated in venom representatives of two 

 distinct classes of proteids, one of which is insoluble in distilled water and coagu- 

 lated in solution by boiling, and another which is soluble in distilled water and 

 non-coagulable by brief boiling; the former belonging to the globulins and the 

 other to the peptones. 



The substance, however, which we find belonging to the globulins is a complex 

 body in its composition, since, by appropriate processes, it can be resolved into three 

 distinct principles, each of which is a globulin, but each having some properties 

 different from its fellows. In order to distinguish these principles Ave have named 

 them water-venom-globidin, copper-venom-globulin, and dialysis-venom-globidin, the 

 names indicating the principal feature of the processes by which they are isolated 

 from each other. As there are some differences in the reactions of similar prin- 

 ciples in different species of venoms, we shall at first speak only of the venom of the 

 Crotalus adamanteus. 



Water-venom-globidin.—We have already stated that when a solution of the 

 fresh or dried venom in distilled water is allowed to stand for some time, especially 

 if the quantity of water be comparatively large, a whitish precipitate occurs which 



