YELLOW FEVER EXPEDITION 
561 
In regard to the pathology of the condition, the circumferential redness is 
suggestive of some chemical as well as of a mere mechanical action ; at the same time 
there does not appear to be any marked effect upon general health. 
These observations were made upon the contents of vesicles occurring upon my 
colleague and myself. 
Treatment. It has already been observed that the lesions in one place resolve 
spontaneously, whether the active agent merely lies latent or actually dies, so that 
reinfection is necessary for the same area to be reinfected cannot be answered. 
The adult natives do not appear to be troubled, but the small babies are often 
seen with what appears to be an identical condition. At the same time, individual 
immunity is not always acquired by long residence, as I met with a gentleman who 
had been about Para for more than ten years, and who said he had never been so 
troubled with prickly heat before, and certainly he was pretty well covered with the 
lesions. 
A considerable number ot different applications were put to the trial. Those 
which were found useless may first be mentioned and disposed of. The ' palliative ' 
applications of toilet powder, of boracic acid in powder or solution, lysol (one per 
cent.), carbolic acid (five per cent.), alcohol, permanganate ot potash, sulphurated 
potash (five to ten per cent., which is quite effective tor dhobie itch), were found to 
be perfectly useless ; they neither relieved the itching nor did they cure the condition. 
Numerous shower baths, whether followed or not by a sponging with weak perman- 
ganate of potash and spontaneous drying, likewise did no good. 
The two applications which were found of service were iodine and corrosive 
sublimate. The former was used in the form of tincture diluted with spirit so as just 
to stain the skin well ; this has the disadvantage of" staining the skin and also marking 
any starched linen temporarily. The corrosive sublimate was used in solution ot about 
1 : 500 to 1 : 1000 in spirit and water, in water alone or in water glycerine and spirit 
(the idea of the glycerine being to prevent irritation by the drug). The first of these 
seemed to be the best, though its superiority was not great over the others, tor plain 
aqueous solution acts perfectly well. The mode of application was to rub well with 
a pledget of cotton-wool well wetted with the solution ; the next day the red inflamed 
areas have disappeared, and the sites of the more deeply infected follicles have a 
brownish colour instead of a bright pink, and on rubbing they are not so irritable. 
Two or three applications may be required to get rid of the deep infections, and it 
seemed more satisfactory to go over considerable areas at a time. The most deeply 
affected follicles are the most difficult to eradicate entirely, and some were treated by 
expression after the manner that the old housewife extracts a wasp sting by means of 
a key barrel, with the pressure of the end of a small glass tube, in which a small 
quantity of the antiseptic solution is held by capillarity. This, which is an effective 
mode of evacuating ordinary suppurating follicles also, is not altogether a pleasant 
