502 



Dr. G. Thin. On Bacterium decalvans. fMar. 3, 



successful in hairs that had been kept for a period of weeks folded in 

 paper, nor in nineteen cultivations attempted with hairs taken from 

 patients under treatment. The negative value of these latter experi- 

 ments is diminished by the occasional failure with hairs freshly 

 extracted from untreated cases. 



The fact that the spores of the Trichophyton will not grow when 

 immersed in vitreous humour, whilst they do grow when only moist- 

 ened by it, explains why inflammatory exudation from the blood- 

 vessels cures ringworm of the scalp. 



III. " On Bacterium decalvans : an Organism associated with the 

 Destruction of the Hair in Alopecia areata." By George 

 Thin, M.D. Communicated by Professor Huxley, Sec. R.S. 

 Received February 19, 1881. 



(Abstract.) 



The author having in several cases of Alopecia areata found bacteria 

 adherent to the roots of extracted hairs, subjected hairs in six selected 

 cases to processes designed to demonstrate the existence of organisms, 

 should they be present, in the substance of the diseased hairs. 



In five out of the six cases an object was observed in the hairs which 

 he believes to be a bacterium. It was seen as a rounded or elongated 

 spheroid, and was found frequently in pairs, the long diameter of the 

 two spheroids forming a continuous straight line. Sometimes three 

 were found in line, a delicate rod-shaped sheath enveloping the three. 

 These bodies were, as was shown by the processes to which the hairs 

 were subjected, neither oily particles nor crystals, and they could be 

 distinguished from the granules always present in hairs. In all the 

 cases their size and form were the same, and they had the refractive 

 qualities of bacteria. 



In hairs which were only slightly affected they were found between 

 the inner root-sheath and the hair-shaft, and in small clusters on 

 the hair-shaft beneath the cuticle of the hair. In hairs which were 

 much diseased they were found in great numbers inside the cuticle of 

 the hair, in the disintegrated hair substance. 



Some hairs were found split into ribbon-like bands not far from the 

 root and the organisms were found on the bands. 



They were found only in the part of the hair which is under the 

 surface of the skin, and most abundantly not far from the root. 



In seven consecutive cases the disease was at once and definitely 

 arrested by a treatment designed to destroy the vitality of any bacteria 

 which might be present on the surface of the skin, and at the same 



