186 VEGETABLE PARASITES. 



points of which meet towards the top of the head. Baume's am- 

 moniacal plaster has been found most advantageous for this purpose. 

 It is prepared by mixing in a porcelain basin, one part of gum 

 ammoniac um and three parts of white- wine vinegar, and which is 

 heated to boiling, then filtered, jy^d two more parts of vinegar 

 added to the solid residue ; the mass is again boiled and filtered, 

 and the filtrate added to the first portion, and allowed to stand for 

 some time, in order to allow foreign bodies to separate and preci- 

 pitate ; the liquid is skimmed off and evaporated at a low tempera- 

 ture, to a syrupy consistence. The strips are covered with this mass, 

 and put on the clean head by means of poultices, or Linimentum 

 Calcis. After two or three days these strips are removed, either 

 all at once, or on alternate days, when the patient is irritable. 

 Many hairs are thus torn out, the skin of the head becomes 

 inflamed, and a great number of pustules usually break out 

 during the following two days, when the head has to be kept 

 uncovered. These pustules are not identical with the favus. 

 When the head is quite bald the ammoniacal plaster is less effec- 

 tive, since, probably, in consequence of a secretion of the skin of 

 the head, the plaster is prevented from sticking so well. Re- 

 course must be had to a plaster of Pix burgundica, Acetum vini, 

 and Amylon, or to the following mixture : R Colophon. $v, Olei 

 5J, Cerse albae 3s ; or IjL Resina fiavee 3J> Amylon Jss, Acet. vini 

 3vj, Ol. oliv. 3iv, Terebinth, ^ss. This process of sticking on 

 and tearing off the plaster must be repeated for several months, 

 at short intervals. The microscope alone can tell when the cure 

 is effected, that is, when all the spores of the fungus have disap- 

 peared, or else there will be new crusts of favi, sometimes after 

 a few weeks only. 



Von Barensprung (' Deutsche Klinik/ No. 6, 1855) employs 

 likewise this modified pitch-cap, and orders precipitate-ointment 

 to be rubbed in, in order to prevent the reappearance of the 

 fungus. 



Boeck tells us that it is one of the injunctions of the founder 

 of the Hospital of St. Gallicano, at Rome, to treat the favus by 

 scarifying the skin of the head ; which was therefore done exten- 

 sively every day, till the whole head had become scarified in the 

 course of a week. The hair is not sacrificed in this process, and 

 one may even succeed in splitting the follicle of the hair, amount- 

 ing, in reality, to the extraction of the hair (epilation). This 

 treatment is, however, admitted by the physicians of the hospital 



