156 PHYSIC 



changes in the non-muscular textural or interstitial ele- 

 ments. 



We may here remark that the chemistry, as well as the 

 bacteriology, of sweat, so far as known to us, do not seem 

 to have been as yet exhaustively investigated, and that, 

 therefore, to us, as holding the view that it (the sweat) 

 may come from both a blood circulatory and a nerve 

 circulatory source, it would appear to be of a consequently 

 variable character, according to which of these sources 

 contributed to the greater extent towards its production 

 for the time being. Moreover, we think it will be found 

 in such investigation work that a considerable exhalation 

 of gaseous material must be reckoned with. 



The stasis of sweat excretion or perspiration, if only 

 local and of short duration, does not necessarily make 

 itself felt pathologically, and, consequently, may pass un- 

 noticed ; but if, on the other hand, it be general and 

 sustained, or often repeated, as in Sir W. Gowers' case, 

 a vague feeling of " aches and pains " is experienced, which 

 may result in rheumatism, more or less acute, neuritis, 

 local or multiple, or myositis, local or general (poly- 

 myositis). 



Rheumatism, acute, subacute, and chronic, has elsewhere 

 been described, neuritis has also been referred to, it, there- 

 fore, now remains for us to explain further the causation 

 and pathological changes observed in myositis and poly- 

 myositis. 



Myositis, however, except for its localisation, being in 

 no way different from poly myositis, it will suffice for us 

 to confine our remarks to the latter disease. 



The cause or causes of poly myositis have almost ex- 

 clusively been attributed to and sought for in the blood 

 supply of the muscles involved, that blood supply being 

 supposed to introduce into the muscular substance or fibre 

 a toxic material or agent, which initiates and perpetuates 

 inflammatory changes sufficient to lead to the destruction 

 and removal, or the disintegration and obliteration, of the 

 muscular discs and fibres, or the sarcous texture proper, 

 accompanied, it may be, by an apparent increase in the 

 fibrous and connective tissue proper of the implicated 

 muscles. Why do we say apparent ? Because we believe 



