Page:Proceedings of the Royal Society of London Vol 60.djvu/367

340 solution. I may here mention that salicylsulphonic acid does not precipitate disintegration products of proteids like leucine, tyrosine, xanthine, or hypoxanthine.

All the precipitates cited above give the colour reactions characteristic of the original substance.

If the original solution is saturated with either magnesium sulphate, ammonium sulphate, or sodium chloride, the whole of the colloid rises to the surface of the liquid, and may be skimmed off. On placing this scum in an excess of distilled water, it rapidly redissolves, forming a pale yellow opalescent solution, which gives all the chemical reactions characteristic of the original substance. If the amount of neutral salt be insufficient to produce precipitation, the passage through the liquid of a current of carbon dioxide or of sulphur dioxide will effect the same result. Neither of these gases will, however, cause precipitation in the entire absence of salts.

The following experiments illustrate the results produced by the intravenous injeqtion of this substance into dogs, rabbits, and cats. The procedure adopted was identical with that described in the previous papers published by Professor Halliburton and myself,# on the intravascular injection of Grimaux’s colloids. In all cases the animal was anaesthetised by a mixture of chloroform and ether, an excess of the latter substance being used when the subjects were dogs.

Experiment 1.—Fox terrier (weight 27 lbs, 10 oz.) ; 25 c.c. of a 0’75 per cent, solution of the colloid a was injected, and proved fatal. Pronounced exophthalmos and dilatation of the pupils, and typical stretching movements were observed.

Post-mortem examination made immediately after death revealed pronounced clots in the jugular vein, inferior vena cava, and portal vein, and a slight dot in the left ventricle and in the pulmonary artery.

Experiment2.—Large black cat (weight 9 lbs. 6 oz.) ; 40. c.c. of the colloid proved fatal, with similar symptoms as above. Immediate post-mortem examination showed pronounced clots in the left ventricle, right auricle, inferior vena cava, portal, and jugular veins. The remainder of the blood was fluid, but coagulated very rapidly after withdrawal.

Experiment3.—Black rabbit; 38 c.c. of the same substance produced a similar result.

Experiment 4.—Albino rabbit; 42 c.c. proved fatal. Death was accompanied by pronounced exophthalmos and dilatation of the pupils and stretching movements of the limbs. Post-mortem examination showed the blood throughout the vessels to be fluid. It, however, rapidly coagulated after withdrawal from the vessels, and the coagulability of samples of the blood taken from the carotids during


 * 1) Op. cit.