APPENDIX. 539 



white sediment, according as blood-corpuscles are or are not 

 present. The urine is acid, neutral, or slightly alkaline, and 

 has a low specific gravity. 



In the second stage the urine is of a clay-yellow colour and 

 turbid, forming a brown sediment ; subsequently the fluid be- 

 comes of a paler colour, of very low specific gravity, and deposits 

 a white flocculent sediment ; and at this period it exhibits a 

 greater tendency to putrefaction than before. 



In the third stage the urine is of a dark red colour, and 

 contains more or less blood ; it also deposits a red or reddish- 

 brown sediment containing numerous blood-corpuscles. It is 

 either ammoniacal on emission, or rapidly becomes so, and its 

 specific gravity is higher than in the other stages. 



The occurrence of blood in the first and third stages is de- 

 pendent on totally different causes. 



In the congestive stage the constituents of the blood enter 

 the urine by the law of endosmosis, and it is not so much 

 actual blood as serum reddened by hsematin in solution that 

 passes over ; in the last stages, however, the capillaries are ac- 

 tually corroded by the morbid process, and then the blood- 

 corpuscles likewise find their way freely into the urine.* Hence 

 in the latter stage the sediment is always of a reddish-brown 

 tint, while in the former it is often white. 



The microscopic appearances are divided by Heller into 

 1, those of constant occurrence, and 2, those occasionally 

 present. 



The constant constituents are : 



. 1. Pavement -epithelium, which is always present, and fre- 

 quently in the congestive stage forms a copious white sediment. 



2. Epithelium from the tubes of Bellini, which usually forms 

 only a slight portion of the sediment in the early stages, al- 

 though sometimes present in large quantity from the com- 

 mencement of the disease. 



3. Albuminous fungi occurring as a clear dotted granular 

 matter in all fluids containing albumen. When they are very 

 abundant the urine developes a mouldy odour. 



4. Mucus-corpuscles. 



5. Granular cells (globules of inflammation) are always to 

 be found during the congestive stage. 



6. Fat- globules, especially in the chronic form of the disease. 



