IMPERFECT NUTRITION : CONSUMPTION. 321 



higher animals at least, do the vessels directly pour the blood 

 into any tissue for the purpose of nourishing it. Unless there 

 have been an actual wound which has artificially opened the 

 blood-vessels, no fluid can escape from them into the substance 

 traversed by the capillaries, except by transuding the walls of 

 the latter ; and hence it would seem impossible that any of 

 the floating cells contained in the blood can be deposited in 

 the tissues and contribute to their development. The Liquor 

 Sanguinis seems, therefore, to furnish all that is wanting for 

 this purpose ; and it readily permeates the walls of the capil- 

 laries, the basement-membrane, and any other of the softer 

 tissues, so as to arrive at the parts where it is to be applied. 

 As it is withdrawn from the blood, it is continually being 

 re-formed from the food ; but if it be not supplied in sufficient 

 quantity by the latter, the tissues are imperfectly nourished, 

 and the strength of the body and the vigour of the mind are 

 consequently alike impaired. 



386. This imperfect nutrition seems to be the essential 

 conditjpn of one of the most destructive diseases to which the 

 human frame is liable, that commonly known as Consump- 

 tion ; which is, however, but one out of several diseases that 

 may result from the same general defect of nutrition. If the 

 liquor sanguinis be imperfectly elaborated, it is less fit to 

 undergo organization ; and, consequently, instead of being 

 converted into living tissue, part of it is deposited, as an 

 imperfectly organized mass, in the state known to the Medical 

 man as Tubercle. Such deposits take place more frequently 

 in the lungs than in any other part ; and besides impeding 

 the circulation and respiration, they produce irritation and 

 inflammation, in the same manner as other substances im- 

 bedded in the tissues would do ; and so far from having, like 

 many other diseases, a natural tendency to cure, this malady, 

 if unchecked, almost certainly leads to a fatal termination. 

 Microscopic examination of tubercular matter shows that it 

 consists of half-formed cells, fibres, &c., together with a granu- 

 lar substance which seems to be little else than coagulated 

 albumen. The only manner in which any curative means can 

 be brought to bear upon this terrible scourge, is by attention 

 to the constitutional state from which it results. This is 

 sometimes hereditary ; and is sometimes induced by insuffi- 

 cient nutrition, obstructed respiration, habitual exposure to 



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