NUTRITION. 251 



of the obstruction. 11 The continuance of circulation was previ- 

 ously attributed solely to the enlargement of the small anasto- 

 mosing vessels; and we know that whenever the aorta itself is 

 obstructed, branches will so enlarge as to carry on the circu- 

 lation very well. Muscle is supplied by tendinous matter. The 

 substance formed in the situation of destroyed cellular mem- 

 brane is so little cellular, that it does not become distended in 

 emphysema or anasarca. p 



" If I am not mistaken, those solid parts undergo successive 

 change, which possess the reproductive power, an extraordinary 

 faculty, by which not only the natural loss of particles, but even 

 the accidental removal of considerable parts through external 

 injuries, is repaired and perfectly supplied, as the bones <i and a 

 few other parts sufficiently demonstrate. 



" In those parts whose vital powers are, as it were, of a higher 

 order, the parenchyma, constituting their base, appears perma- 

 nent, and is liable to this change only, that the interstices of 

 the fibres and parenchyma, while nutrition is vigorous, are con- 

 stantly full of nutrient animal " soft substance ; " but, when nutri- 

 tion languishes, are deprived of this, collapse, and consequently 

 become thin." The very convolutions of the brain will shrink in 

 extreme emaciation. 



" During the growth of the body, peculiar powers are exerted, 

 by which the fibrin deposited in the cellular membrane from the 

 blood-vessels is properly distributed and intimately assimilated to 

 the substance of each organ, &c. 



n An Experimental Inquiry, <fyc. See also Dr. Charles Parry's work, in which 

 similar experiments are related. 



See a case in the Dublin Hospital Reports, vol. ii. Med. Chir. Trans, vol. v. 



p Dr. Thomson, Lectures on Inflammation, p. 417. 



9 " Consult, among others, G. L. Koeler, Experimenta circa regenerationem 

 ossium. Gotting. 1786. 8vo. 



Alex. Herm. Macdonald, De necrosi ac callo. Edinb. 1799. 8vo " 



" That the corium is not really reproduced, is probable, not only from its per- 

 petual cicatrices (for some contend that the matter of these does not continue, but 

 their/orm only, which is preserved by a perpetual apposition of fresh particles in 

 the room of the decayed and absorbed), but much more by the lines and figures 

 which are made upon the skin by the singular art of pricking it with a needle 

 (a process denominated in the barbarous language of the Otaheiteans tfttooing), 

 and imparting to the corium a blue or red colour, as permanent as the cicatricula;, 

 by means of charcoal powder, ashes, soot, the juices of plants, or ox-gall; while, 

 on the other hand, the red hue imparted to the bones, by means of madder, 

 quickly disappears, as these parts undergo a continual renovation." 



