Page:Proceedings of the Royal Society of London Vol 60.djvu/375

343 The colloid // coagulates only at 52° C.

Adopting tlie conclusion of Halliburton that the precipitates obtained by the fractional heat coagulation of a proteid substance, correspond with various constituents of that substance, we may possibly conclude that those synthesised colloids which yield fractional heat-coagula are mixtures of different colloidal substances.

Thus the colloid B would consist of two substances which might be designated B! and B2, and the colloid /3 of three substances, designated colloids /i2, and /33 respectively, and the colloid of two substances, c,l and 82. I have endeavoured to ascertain in the cases of the colloids B! and B2 and of the colloids (3U and /?3 whether each of these substances will equally induce intravascular coagulation of the blood, when intravenously injected into pigmented rabbits and dogs.

The method of procedure adopted was briefly as follows :—The activity of a solution of the colloid was tested by a control experiment. One of the constituents was removed by fractional heatcoagulation and the effect, if any, produced by the intravascular injection of the remaining colloid in solution was tested.41 The following is the record of some of the results obtained:—

Colloid B2 after a removal of colloid Bt will, if intravenously injected, induce intravascular coagulation in pigmented rabbits, and if slowly injected in minute doses a “ negative phase ” in dogs.

Colloids ft2and fi3 will still, after the removal of colloid /3U induce intravascular coagulation in pigmented rabbits, although a much larger dose is required after the removal of /3t and [i2 than if the mixture of the three substances is injected, if only is removed the activity of the mixture is not impaired. From this I conclude that ji2 and fi3 are the active constituents of the colloid mixture I have designated as the colloid /3. There is apparently no difference in the tendency to induce a “ negative phase” in dog’s blood after the removal of fix and from the solution.

The influence of these substances on red and white blood corpuscles, and on extravascular 1 per cent, sodium carbonate plasma will be described in a subsequent paper.

It is evident from the observations recorded in the preceding pages, that if certain derivatives of proteids, and other substances of

the original solution.
 * The solution after removal of one of its constituents by fractional heatcoagulation, was evaporated down in vacuo until it had the same specific gravity as