According to C. J. Martin and MacGarvie Smith, the albumoses of the venoms of Colubridæ are hetero-albumoses, proto-albumoses, and perhaps deutero-albumoses in small quantities. They can be separated in the following manner:—
The solution of venom is heated to 90° C., and filtered in order to separate the albumins coagulable by heat. The filtrate, saturated with sulphate of magnesium, is shaken for twelve hours. By this means there is obtained a flocculent precipitate, which is placed upon a filter and washed with a saturated solution of sulphate of magnesium. The filtrate is dialysed for twenty-four hours in a stream of distilled water, and then concentrated, likewise by dialysis, in absolute alcohol. Thus we obtain a few cubic centimetres of liquid, which contains a small quantity of proteids in solution. These proteids can be nothing but a mixture of proto- and deutero-albumoses with peptones. That there is actually no trace of the latter can easily be ascertained.
Neumeister[9] has shown that it is impossible to precipitate all the proto-albumoses of a solution by saturation with neutral salts, and, since the filtrate becomes slightly turbid when a few drops of a 5 per cent. solution of sulphate of copper are added to it, we must conclude that it contains a small proportion of these proto-albumoses.
The deposit retained upon the filter after washing with sulphate of magnesium is redissolved in distilled water, and dialysed for three days. An abundant precipitate then becomes collected in the dialyser. This is centrifuged. The clear liquid is decanted with a pipette, then concentrated by dialysis in absolute alcohol, and finally evaporated at 40° C. until completely desiccated. The solid residue is washed and centrifuged several times in distilled water, after which it is dried on chloride of sodium.
This method enables us to separate two albumoses, both precipitable by saturation with sulphate of magnesium, and belonging to the class of primary albumoses: one of these, proto-albumose, is soluble in distilled water, the other, hetero-albumose, is insoluble; but the latter can be dissolved in dilute solutions of neutral salts. These bodies are respectively identical with those obtained by the pepsic digestion of proteids.[10]
In order to study separately the local and general effects of these different albumoses, C. J. Martin and MacGarvie Smith performed the following experiment:—
They introduced beneath the skin of the belly of a guinea-pig, previously shaved and rendered aseptic, two small pieces of sterilized sponge, about 2 c.mm., one of which was impregnated with the solution of proteid, while the other served as control. The two small incisions, one on either side of the median line, were then sutured and covered with collodion. In this way the maximum of local effect and the minimum of general effects was obtained. The solutions of albumoses introduced by this method into the organism produced an enormous œdema, which, in from six to eight hours, extended along the whole side of the abdomen containing the sponge charged with poison.
To test the general toxic effects, the solutions were injected into a vein or into the peritoneal cavity. It was thus found that the proto- and hetero-albumoses killed the animals in a few hours.
It must therefore be concluded from these facts that the active principles of venom are proto- and hetero-albumoses, the albumins that it contains being devoid of all toxic power.