508 Messrs. H. G. Plimmer and J. D. Thomson. [July 20, 



cases after atoxyl a temporary disappearance of the trypanosomes was also 

 effected. 



Other Arsenic Com/pounds. 



Arrhenal (cli-methyl sodium arseniate) and sodium cacodylate were 

 also tried, but were found to have no effect whatever on the course of the 

 disease, nor upon the development of the trypanosomes either in first infections 

 or in recurrences. 



Other Bodies. 



Fluorescein was tried without any effect ; and also sodium ciimamate, on 

 account of its reputed property of producing leucocytosis, which might have 

 been useful from the phagocytic standpoint. But it failed to have any effect 

 in these diseases. 



Treatment with two or more Drugs. 



The deduction from the above-mentioned experiments with single bodies 

 is that, at the present time, there is no substance known which alone will 

 cause a permanent disappearance of the trypanosomes from the affected 

 animal, i.e., effect a cure ; so that experiments have been carried out to see 

 whether any combination of bodies would produce the desired effect. The 

 compounds of mercury seemed from their known properties to be the most 

 promising, and the results of experiments in this direction, lately published 

 by Drs. Moore, Nierenstein, and Todd, are most encouraging. We have not 

 used the form of mercury (liq. hydrarg. perchlor.) with which these good 

 results have been obtained, but we have used the lactate, sozoiodol, and 

 succinimide, and also Donovan's Solution (liq. arsen. et hydrarg. iodid.). Of 

 these the succinimide appears to us to be the best, as it is unirritating, and 

 will apparently mix with atoxyl without change — at any rate it does not 

 interfere with the action of the atoxyl ; the lactate is very irritating, even in 

 doses of one-third of a minim of the ordinary hypodermic solution, and it is 

 not so effective as the succinimide ; the sozoiodol appears to come between 

 these two in point of efficiency. But in our experience there is a great 

 difference in the individual equation of rats with regard to dosage and 

 poisonous effects, which the consideration of relative weight does not help us 

 to gauge, so that there has been difficulty in ensuring the best method of 

 giving these drugs, and of determining their appropriate quantity. The 

 duration of the disease has been very greatly prolonged in most cases, and in 

 some we have confidence that a cure has been effected. 



Of all the substances tried, atoxyl has had by far the most favourable 

 action, and it is easily tolerated, and produces no irritation. But, as mentioned 

 before, it has no permanent effect ; it causes the disappearance of the 



