216 UNORGANISED FLUIDS. 



ferable, the albumen being held in solution by the free 

 alkalies. 



Urine may, however, become turbid from the application 

 of heat, even when no albumen is present : this arises from 

 precipitation of the earthy carbonates; in these instances, 

 the addition of nitric acid will immediately disperse the 

 cloudiness, and the reapplication of heat will not occasion 

 any further precipitation. 



Dr. Gr. O. Rees has observed that the urine of persons 

 who have been taking cubebs or balsam of copaiba is ren- 

 dered turbid by nitric acid, although it contains no albumen : 

 this urine, however, is not affected by heat. 



From the facts contained in the two preceding paragraphs, 

 it follows that a precipitate might possibly ensue on the ap- 

 plication of heat, and by the addition of nitric acid, and yet 

 no albumen be present in the urine. 



If the precipitate yielded by nitric acid, added to urine 

 impregnated with the active principles of cubebs or copaiba, 

 be examined with the microscope, it will be found to consist 

 of minute oil bubbles, which are of course readily soluble 

 in ether. 



Fibrinous Urine. 



Fibrin has been encountered in the urine independently 

 of the other constituents of the blood : Zimmerman * has 

 described seven cases of fibrinous urine. 



Such urine, if the fibrin existed in it in any quantity, 

 would coagulate or form a clot. 



It is necessary in these cases not to confound mucus with 

 fibrin ; the former, under the microscope, exhibits the well- 

 known mucous corpuscles, while the latter appears either 

 filamentous or simply granular. 



Fatty Urine. 



The urine may contain fat, either separately or conjointly 

 with albumen, or with casein, and probably also sugar : the 



* Zur Analysis und Sunthesis der pseudoplastischen Prozesse, Berlin, 

 1844. p. 129. 



