460 THE SOLIDS. 



" 1st. Acute desquamative nephritis : 



" 2d. Chronic desquamative nephritis : 



" 3d. Simple fatty degeneration : and 



u 4th. A combination of fatty degeneration with desquamative nephritis. 



" The diagnosis of each of these conditions of the kidney, during the 

 life of the patient, is a matter of the greatest importance with reference 

 to prognosis and treatment ; and the diagnosis may be made with ease 

 and certainty by a microscopical examination of the urine." 



The most recent researches in this country into the patho- 

 logical anatomy of the kidneys are those of Dr. Gairdner *, 

 who has evidently devoted to the elucidation of this subject 

 not a little time and attention ; and the results of these in- 

 vestigations will now be given in as concise a form as 

 possible. 



Dr. Gairdner treats of his subject under the three following heads : 

 1. Exudation: 2. Lesions affecting chiefly the vascular system: and 

 3. Lesions of the tubes and epithelium an arrangement which will here 

 be followed. 



Exudation. 



Exudations into the substance of the kidney give rise to a great 

 variety of external appearances, which have been well figured and de- 

 scribed in the works of Bright and Rayer. 



Exudations from the blood-vessels may have their seat in any, or all 

 the tissues of the kidney ; their usual situation, however, is in the in- 

 terior of the tubes, but it also occurs frequently within and around the 

 Malpighian bodies, and in the intertubular tissue, the tubes being quite 

 clear ; it is also seen infiltrated through all the tissues in the form of a 

 homogeneous mass, which contained within it the whole of the anatomical 

 elements of the kidney. 



The appearance of the kidney, as altered by the presence of exudation 

 in the tubes, is subject to variations depending on the amount of the 

 deposition, and its partial or general character : one almost invariable 

 effect of the repletion of the tubes, is a corresponding diminution in the 

 fulness of the vessels of the cortical substance, particularly of the Mal- 

 pighian vessels, and the capillaries surrounding the tubes. This effect is 

 evidently the result of pressure. 



It is thus evident that Dr. Gairdner does not ascribe the albuminous 

 urine of Bright's disease to secondary congestion, or rupture of the 

 Malpighian bodies, caused by the distention of the tubes from accu- 



* Contributions to the Pathology of the Kidney, by William T. Gaird- 

 ner, M.D. Monthly Journal of Medical Science, 1848. 



