462 THE SOLIDS. 



The facts connected with the presence of fatty exudations in the 

 kidney, have been almost exhausted by the excellent researches of Dr. 

 Johnson ; one additional fact of interest has been added by Dr. Gairdner. 

 This observer finds that the fatty granules or globules are not confined 

 to the epithelial cells, but also that they may be freely disseminated 

 throughout the tubes : the tubes containing the fatty granules sometimes 

 appear distended, at other times smaller than natural, as if they had 

 contracted around the fat. 



It is probable that the presence of the fatty globules in the tubes 

 results from the rupture and disorganisation of the cells which first con- 

 tained them, and that, therefore, their location in the tubes themselves 

 indicates a more advanced condition of this form of renal disorganisation. 



c. The occurrence in the cortical substance of deposits of pus is not 

 very uncommon : their most usual form is that of small abscesses, rarely 

 exceeding the size of a pea, and frequently much smaller ; sometimes con- 

 fluent, and irregularly disseminated throughout the cortical substance. 



The granular (oleo-albuminous) form of exudation is frequently found 

 occupying the tubes of the kidney, and occasionally also within the 

 capsules of the Malpighian bodies : when in large quantity in the 

 latter situation, the tuft of vessels becomes compressed, shrunk, and, in 

 most cases, invisible. 



Under the heading " Partial distribution of the oleo-albuminous ex- 

 udation," Dr. Gairdner describes, in the following terms, a peculiar 

 pathological condition of the kidney: "I have already described the 

 formation of granulations as dependant on the accumulation of deposit 

 in particular groups of tubules in the cortical substance. In such cases, 

 however, the affection is probably, at first, general ; they are very dif- 

 ferent from the form now to be described, in which the deposit is quite 

 limited in extent, and isolated. 



" There are occasionally met with, on removing the capsule from 

 the surface of a kidney, irregular patches, of a paler colour than the 

 rest of the organ, sometimes a little elevated, sometimes depressed below 

 the general surface. Their boundary is quite abrupt, and they are fre- 

 quently surrounded by a well-marked rose-coloured areola, extending 

 more or less into the surrounding substance. On making a section of 

 these patches, they are found to penetrate into the cortical substance, 

 and sometimes even a certain way into the pyramids. The vascular 

 areola, when present, extends round them in every direction, and is 

 found, on examination, to consist of highly-injected Malpighian bodies 

 and capillaries, with or without extravasation ; the colour of the patches 

 varies from yellowish-grey to gamboge-yellow : their consistence is ge- 

 nerally firm. On microscopic examination, they present a large amount 

 of exudation, varying from the molecular to the large granular form. 

 In some cases the tubes may be seen filled with exudation ; in others 

 they appear to be in great part obliterated. In one case I found the 

 Malpighian bodies quite free of exudation ; they preserved their usual 



