I 



250 Mr. Thomson and Dr. Cushny. On the Action of [Nov. 23, 



which antimony is more firmly combined than the ordinary salts, but very 

 few organic combinations are available, and we have succeeded in obtaining 

 only two such for investigation. Of these the first was tetraethylstibonium 

 iodide ( (C2H5)4SbI), which was injected into seven Nagana rats in quantities 

 up to 20 milligrammes, but had no effect whatever on the parasites, the 

 injected animals dying at the usual time, and the blood being found to 

 be swarming with trypanosomes. The other, diphenylstibinchloride 

 ( (CBH6)2SbCl3, H2O), was kindly put at our disposal by Prof. A. Michaelis, 

 of Kostock, but proved quite devoid of action in quantities of 4 c.c. of a 

 saturated solution in sodium carbonate, in which it is more soluble than in 

 water. These compounds appear non-irritant, but the antimony is probably 

 not freed in the tissues, the first compound in particular resembling the 

 ammonium salts, which pass through the animal body without freeing nitrogen. 



These compounds proving valueless for our purpose, it was determined to 

 find in what form the antimony ion had to be liberated to be effective, and 

 a number of compounds commercially obtainable were tested. Of these 

 the potassium metantimoniate (Sb020K), injected in quantities up to 

 30 milligrammes, scarcely affected tha trypanosomes in the blood ; doses 

 above 30 milligrammes were followed by the disappearance of the parasites 

 from the circulation, but the rats became very ill and died within a few 

 days, and post mortem enteritis and nephritis were found to have been 

 developed. A preparation of antimony oxide (Sb203), stated to be in 

 colloidal form, was obtained from Kalle and Co., but proved extremely 

 irritating, and had a very low efficiency. The preparation contained 4'5 per 

 cent, of antimony oxide only, and in quantities corresponding to 4 milli- 

 grammes of the oxide had little, if any, effect in reducing the number of 

 trypanosomes in the blood ; 8 milligrammes caused their disappearance, but 

 they recurred on the fourth day. 



In the former of these preparations antimony is presented in pentavalont, 

 in the latter in trivalent, form, and both are equally inefficient, while in 

 the forms in which it is presented in combination with organic acids it is 

 also in trivalent foi'U), but has been shown to have a high degree of activity. 

 It is possible that, given in the colloid form, it is deposited locally and fails 

 to reach the trypanosomes. This would also explain the intense local action, 

 whicli was more marked from this than from any other preparation. 



A glyceride of antimony, analogous to boroglyceride, was formed by 

 heating glycerine with tlie oxide, and proved fairly effective in destroying 

 the trypanosomes in the raus, but it was very irritant and caused lucmo- 

 globinuria, and tlu; solution in glycerine tended to deposit the oxide when 

 diluted. 



