LEPllOSY. 



385 



and BoecFs work on the Norwegian Spedalsked appeared in 

 Paris, a work illustrated with admirable drawins^s. Since then 

 Virclioio has taken the matter in hand, and has subjected it to a 

 most exhaustive treatment in his work on Tumours. All the 

 affections observed in the course of leprosy are based, histolo- 

 gically speaking, on a common foundation. This is a change 

 in the connective tissue which leads, in the skin, to the 

 formation of the well-known leprous tubercles. After a pro- 

 longed initiatory stage, during which the skin is reddened in 

 patches and exhibits bossy swellings, a number of nodules arc 

 developed in the substance of the cutis or in the subcutaneous 

 tissue ; these vary in size from a hazel-nut to a walnut ; they arc 

 hard, and more or less prominent according to their situation. 

 They give the skin a tuberculated aspect ; occurring by pre- 

 ference upon the face and hands, they lead to the most repulsive 

 deformities. Microscopical analysis in the hands of Virchoiv 

 yielded invariably the same results. The nodules consisted 

 throughout of granulation-tissue, very rich in cells. This tissue 

 extended from the rete Malpighii to the subcutaneous layer of 

 adipose tissue ; it surrounded the hair-sacs and sebaceous glands, 

 causing their atrophy by disturb- 

 ing their nutrition. Hence it is 

 that the tubercles of leprosy, even 

 Avhen seated on the hairy scalp, 

 are always hairless. The accom- 

 panying woodcut is copied from 

 fio;. 178 in VircJioiu's book on 

 Tumours, and shows the leprous 

 tissue under a considerable magni- 

 fving power. Virclww adds that he 

 has nowhere traced the progressive 

 development of a simple sjnndle- 

 shaped or stellate connective-tissue 

 corpuscle through all the stages of 

 nuclear and corpuscular prolifera- 

 tion so perfectly as here. The cells 

 divide; they grow smaller and 

 more numerous ; the intercellular 

 substance is represented by very narrow bands of a materia 

 Avhich is rendered granular and cloudy by acetic acid, and whicl 



25 



Fig. 119. 



Tissue of leprous tubercles 

 (after Virchovj). Cells un- 

 dergoing division. 



