PRODUCTS, ADVENTITIOUS. 



(6.) Fibrin retained. The majority of pro- 

 tein-precipitates are probably fibrinous. At 

 least spontaneous coagulation (a quality be' 

 longing to them alone) is by far the most 

 readily conceivable cause of precipitation 

 under the circumstances now pointed at. 



Fibrin occasionally occurs as a potential 

 precipitate in the fluid of dropsies, a fact 

 which will be further considered in Part II. 



(C.) Casein occurs in combination with fat 

 in so-called "milky" urine. 



(D.) Globulin is practically unknown (as 

 distinguishable from the other protein-com- 

 pounds) in the present point of view : it pro- 

 bably forms the substance of some granular 

 precipitates. 



II. FAT. Considered in respect of their 

 ultimate physical elements, the varieties of fat 

 (known to occur as morbid products) appear 

 as adipose cells, free-fluid oil-globules (olein); 

 solid fat granules (mainly margarin) ; groups 

 of stellate crystals (margarin and margaric 

 acid) ; rhomboidal plates (cholesterin). Fat 

 may likewise be incorporated in such manner 

 with the textures as to be only chemically 

 discoverable, a fact often lost sight of in the 

 examination of morbid appearances : phos- 

 phuretted fat has thus (among other examples 

 of the fact) been found in cancer. Of serolin 

 as a new product nothing is known. 



Unhealthy formation of fatty and oily sub- 

 stance is of almost perpetual occurrence. The 

 fat produced is either similar (when viewed 

 with the naked eye) to that naturally filling the 

 cells of adipose tissue, or more or less com- 

 pletely dissimilar. In \hefirst case the na- 

 tural adipose structure is simply present in 

 excess, whence arise local or general obesity, 

 fatty infiltration of parts, and lipomatous tu- 

 mours. In these conditions there is little more 

 than hypertrophy or excessive secretion ; and 

 it is mainly in deference to usage that we shall, 

 in another part of this article, describe lipoma 

 as an adventitious product. In the $econd 

 case the dissimilarity of the fatty material to 

 natural fat, or the new situation in which it 

 appears, gives it the character of adventitious- 

 ness. Here we shall find: (A) certain va- 

 rieties of fatty infiltration of natural or of 

 adventitious structures; (B) fatty matters ex- 

 creted in the semi-fluid state; (C) encysted 

 fats ; (D) cholesteric and laminated fats. 



(A.) Fatty infiltration, (a) Liver. The 

 existence of oily matter, as one of the natural 

 constituents of the liver, long since proved 

 chemically by Braconnot, was some years 

 since established with the microscope, by 



Fig. 89. 



Gluge*, and more recently with greater pre- 

 cision by Mr. Bowman f, who displayed the 

 position of the oil-globules in the elementary 

 cells of the healthy organ. Now fatty infil- 

 tration may occur from superabundant depo- 

 sition of the natural oil, or from that of oily 

 matter differing from this in chemical con- 

 stitution. 



(1.) The liver, when "fatty," is increased, 

 in some cases enormously, in size ; its rela- 

 tions of shape remain unaltered. It is, by far 

 the most frequently affected equally through 

 its entire substance ; but we have, in rare in- 

 stances, seen the infiltration specially impli- 

 cating islets of the organ ; its colour is pale 

 greenish yellow or faded leaf; sometimes but 

 rarely studded with reddish points ; its elas- 

 ticity destroyed to such a degree that it pits 

 on pressure ; its consistence greatly dimi- 

 nished; its density decreased to so great an 

 amount that slices have been known to float 

 in water. Very rarely is this condition of the 

 liver coexistent with other morbid changes in 

 its substance ; the vessels and ducts are un- 

 changed in calibre and structure. 



The fatty nature of the impregnation is 

 sometimes obvious on the most superficial 

 inspection ; the hands and knives brought in 

 contact with the tissue are greased ; and if a 

 thin slice be placed on paper and exposed to 

 heat, the fatty matter melts abundantly, and 

 oils the paper. Gluge was the first to show 

 that these appearances depend upon the accu- 

 mulation of a multitude of free fat globules, 

 with a small quantity of yellowish granular 

 matter, probably belonging to the colouring 

 matter of the bile. Mr. Bowman discovered 

 the precise seat of the morbid deposition to 

 be the interior of the elementary liver-cells : 

 " instead of containing a few minute scattered 

 globules, the nucleated particles are gorged 

 with large masses of it, which greatly augment 

 their bulk, and more or less obscure their 

 nuclei." 



Fig. 90. 



Nucleated particles from the healthy human liver. 



(After Bowman.) 

 a, nuclei ; 6, nucleoli ; c, fatty globules. 



Nucleated particles from the liver affected with fatty 



degeneration. (After Bowman.) 

 a, nuclei ; b, nucleoli ; c, c, fatty globules. 

 We believe, however, with Mr. Gulliver , 

 that in this morbid state fat accumulates " in 

 the interlobular fissures and spaces, as de- 

 scribed by Mr. Kiernan, or at least around 

 the surface of the lobules, where it forms a 

 distinct buff-coloured boundary to each of 

 them. The ruddy-coloured hepatic lobules 

 appear to diminish in size as the paler fatty 

 substance increases. In a few instances it 

 was principally seated in the centre of the 

 lobules." Albers$ taught that the fat depo- 



* Op. cit. Heft i. S. 126. 1838. 

 f Lancet, January, 1842. 

 t Med. Chir. Trans, vol. xxvi. p. 9G. 

 Rust's Magazin, 1839. 



