ALBUMINOUS COMPOUNDS. 61 



this analogy. Thus, just as crystals will form around a nucleus of the same 

 kind, from a solution which would not otherwise have deposited them, so will a 

 fibrinous coagulum often separate from a serous fluid, and form around a piece of 

 washed clot of blood, or of the buffy coat, or of muscle or some other animal tissue 

 placed in it, although the fluid (such as that of hydrocele) would not have 

 otherwise shown any disposition to coagulate. 1 It is to be remembered, how- 

 ever, that the processes of crystallization and fibrillation cannot be more closely 

 likened, either in their conditions or in their results ; for the latter occurs only 

 in a substance which has been removed by vital action from the category of 

 ordinary chemical compounds, and it produces a distinctly organic form ; whilst 

 in crystallization we have a typical example of the exertion of the purely 

 physical forces, tending to produce a perfectly symmetrical and homogeneous 

 body, whose shape is characteristically that of inorganic or mineral substances. 

 27. The degree of regularity with which this fibrillation takes place, and 

 the completeness of the fibres which are formed by it, seem to depend especially 

 upon two conditions : 1st, the degree of previous elaboration to which the. fibrin 

 has been subjected; and 2d, the properties of the surface on which it takes 

 place. Thus we find the coagulum of some specimens of blood to be much 

 firmer, and its fibrous structure to be more distinct, than that of others ; the fibril- 

 lation of the fibrinous fluid of inflammatory blood is usually more complete than 

 that of ordinary blood; and that of the fluid of plastic exudations, formerly 

 known as "coagulable lymph/' is still more distinct. But further, the fibrilla- 

 tion takes place far more perfectly when the fibrinous fluid is effused on a living 

 surface, than when it is spread out over dead matter; and thus it happens that 

 fibrinous effusions are much more completely converted into fibrous tissue within 

 the living body, and in immediate contact with living tissue, than they ever are 

 when removed from it. A marked difference may be observed in this respect, 

 between the superficial and the central portions of a blood-clot which has been 

 effused in the substance of the living solids ; for it is always in the former that 

 the organizing process is most advanced, a firm and distinct fibrous membrane 

 being often found on the exterior of such clots, whilst their interior is soft and 

 amorphous. 3 Generally speaking, the 



fibrillation is more perfect, the more Fig. 2. 



slowly it takes place ; and the higher the 

 previous vitalization of the fibrin, the 

 longer is it before it changes its state. 

 Thus the coagulation of sthenic inflam- 

 matory blood, which produces a clot of 

 remarkable firmness, is much longer in 

 taking place than the coagulation of ordi- 

 nary blood; whilst the coagulation of the 

 blood of cachectic subjects, which takes 

 place very rapidly, is feeble and imper- 

 fect. The plastic effusions .poured out 

 from the blood in these two opposite 

 conditions, partake of the character of ,,., 



xu vi j -x ix- xi. e xi. a Fibrous structure of inflammatory exudation 



the blood itself ; those of the mflamma- from peritoneum. 



tory blood of a previously healthy subject 



being converted into fibrous membranes of considerable firmness (Fig. 2), which 



^ ! Such appears to the Author to be the true view of the results of the interesting expe- 

 riments of Prof. Buchanan of Glasgow; for an account of which see the " Proceedings of 

 the Glasgow Philosophical Society" for 1845, and the "Medical Gazette" for 1836 pp 52 

 and 90, and for 1845, p. 617, et seq. 



2 See Dr. G. Burrows, in "Medical Gazette," 1835; and Mr. Prescott Hewett in 

 " Medico-Chirurg. Trans." 1845. 



