On Bacterium decalvans. 



249 



of this disease I always looked for evidences of tlie presence of 

 bacteria. The difficulty of distinguishing in a fluid minute granules 

 from micrococci or from the spore forms of rod bacteria, is so great, 

 that it was only when the characteristic appearances of elongating 

 spheroids or small rod-shaped bodies containing spheroidal ele- 

 ments, arranged linearly, or rod bacteria were observed, that the 

 evidence of the presence of organisms was deemed conclusive. These 

 were, however, observed sufficiently often to satisfy me that their 

 presence was probably more than accidental, and to induce me to 

 submit the affected hairs to various processes with the view of enabling 

 the contents of the hair shaft to be better observed. 



During the year 1880 six cases were specially utilised for this 

 purpose, and, as in all these cases, a considerable number of hairs, in 

 several of them a large number, were examined and submitted to 

 methods of examination eminently fitted to display a fungus, if 

 such were present, it may be nseful to state in further confirmation 

 of the opinions generally entertained, that in none of them any more 

 than in those previously observed, was any fungus discovered.* 



All these six cases were unmistakable examples of alopecia areata. 

 Evidence that this was so would be out of place in this paper, but 

 will be given in due time in a professional journal in connexion with 

 a description of the treatment under which the disease was in all of 

 them at once arrested. f 



The treatment referred to was based on the evidence which, by this 

 time I believed 1 had obtained, that the progress of the disease was 

 due to the development of a bacterium. 



In utilising these cases for the demonstration of an organism, my 

 object was not so much to observe bacteria in fluids in which the hairs 

 were examined, as to endeavour to find some method by which their 

 presence could be shown in the substance of the hair. In five of the 

 six cases I satisfied myself that this had been done. This demonstra- 

 tion is attended with great difficulty. In a comparatively sound hair 

 it is very difficult to bring minute objects like bacteria under observa- 

 tion, and in hairs which are considerably affected the shaft is found , 

 when prepared for examination, to be so full of pigment and other 

 granules that it becomes very difficult to distinguish organisms 

 amongst them, presuming these to be present. 



The methods employed were the following : — 



* The extent to which these investigations have been carried, more especially as 

 regards the number of hairs examined in some of the cases, leads me to believe that 

 those authors who have described a fungus in alopecia areata made a mistaken 

 diagnosis, and that their cases were examples of ringworm in which the growth of 

 the trichophyton had produced comparatively little reaction in the skin. 



f As I am familiar with the disease, for the purposes of this paper my statement 

 as regards the diagnosis may be considered sufficient. 



