URINE. 189 



observed: and upon kneading the clot in water we obtain fibrin, 

 which may be washed perfectly pure. Under these circum- 

 stances there is no difficulty in ascertaining the presence of 

 blood. If the blood has coagulated in the bladder, the urine 

 will be of a blood or brown-red colour, or even of a brownish- 

 black, and will contain gelatinous flocculent coagula of fibrin, 

 which, after remaining for some time in the urine may acquire 

 a degree of transparency by the solution of their colouring 

 matter. 



It is only necessary, in these cases, to make sure that the 

 coagula are not composed of mucus, a point which can be readily 

 settled by the microscope, under which coagula of fibrin, upon 

 compression between thin glass plates^ present an amorphous 

 granular appearance, while in the mucus-flocculi we recognize 

 the well-known mucus- granules. 



The quantitative determination of the constituents of the 

 blood must be conducted in the manner described in 2. A 

 method perfectly similar to the one which I have given for the 

 analysis of blood may, however, be adopted, and in order to 

 determine the urea in a certain quantity of bloody urine, the 

 protein-compounds must be precipitated with alcohol, in the 

 same manner as in albuminous urine. 



4. Urine may contain fat either as an independent extra- 

 neous constituent, or associated with albumen, or with casein 

 and the other constituents of milk. To distinguish these three 

 morbid forms of urine we may term them, for brevity, fatty 

 urine, cltylous urine (Prout), and milky urine. In addition to 

 these forms, urine containing blood always contains, of course, 

 a relatively corresponding quantity of fat. 



Fatty urine. We occasionally observe that the urine of 

 persons labouring under consumptive disorders becomes covered 

 over with a glistening film. It would be precipitate to consider 

 this, without further investigation, as a fatty coat, since I have 

 observed a similar appearance on the surface of urine which had 

 been standing for some time, and was just becoming ammoniacal. 

 The microscope will immediately disclose the nature of the film : 

 if it is composed of fat, we observe, on the microscopic exa- 

 mination of a small portion, an immense number of fat-globules ; 



