46 ANIMAL PARASITES. 



eggs, but only suspends it, and hence relapses occur after six, 

 eight, or even twelve weeks. According to Volz, it would be 

 rational to effect a rubbing on the first, tenth, and twentieth days, 

 and to take baths in the intervals, as in this way any brood ex- 

 cluded subsequently would be killed, and their development to 

 maturity prevented. In general, *this process is not adapted for a 

 hospital treatment, but furnishes a good preliminary treatment. 



The oils here referred to are interesting in a physiological 

 point of view, as they prove that the mites must possess a respi- 

 ratory organ, through which their poisonous action upon the 

 animals is communicated. 



Solutions of Delphinine have not proved to be Antisarcoptica 

 with me. Nor do I expect anything from the Tinctura Staphis- 

 agrise, nor from the powder of the seeds of the same remedy, 

 notwithstanding Bourguignon's recommendation, as the mites do 

 not certainly die in them. 



With the action of the Tinctura Tabaci, and of the solution or ex- 

 tract of the so-called insect-powder (see Lice), I am unacquainted. 



I now come to the method which is at present most widely 

 and generally diffused, Hardy's rapid cure and its modifications, 

 which I place here, because the principal agent in it is certainly, 

 as Volz first stated, the carbonate of potash, or the alkaline 

 sulphuret which may be formed, in which the mites soon (within 

 a quarter of an hour) become pale and transparent, and die. 



The method introduced by Bazin and Hardy is only a repe- 

 tition of that employed by Bourdin, as early as 1812, at the hos- 

 pital of St. Louis, in which Helmericlr's ointment, which still main- 

 tained its ground at this hospital, plays a principal part. Bourdin 

 first of all gave a purifying bath, and at the same time had soft 

 soap rubbed into the whole body for half an hour; 2dly, on the next 

 day he had the whole body rubbed three times with Helmerich's 

 alkaline sulphur-ointment (8 parts of lard, 2 of sulphur, 4 of car- 

 bonate of potash) ; and 3dly, on the second day he gave a purifying 

 bath of soap, after which the patient was discharged as cured. Hardy 

 abridged this process essentially. After the rubbing in of soft 

 soap for half an hour, the patient goes into the bath, where he 

 is again rubbed for an hour with soft soap, and after the bath for 

 half an hour with Ilelmerich^s ointment. In this way, according 

 to Volz, 3 4 ounces of ointment and a pound of soft soap are 

 used to one patient. Unfortunately, this method affords no pro- 

 tection against relapses, produces extensive eczema, and even 



