696 



APPENDIX. 



having been met with in the uriniferous tubes after death, and 

 in fibrinous casts of those tubes. Phosphate of lime and lithic 

 acid also assume the dumb-bell form ; but the solubility in pot- 

 ash, and the different refracting power of these latter crystals, 

 distinguish them from those of the oxalate. 



FIG. 420. 



Lithates constitute the so-called "lateritious deposits" in urine. 

 According to Heintz these buff-colored or deep red sediments 

 consist mainly of lithate of soda mixed with small portions of 

 the lithates of ammonia and lime, and a trace of the lithate of 

 magnesia. Under the microscope they appear as minute granules 

 in different states of aggregation. (Fig. 420.) The lithates of 

 ammonia and soda sometimes occur in spherical masses, adher- 

 ing to thin films of the phosphates. The ammoniacal lithate 

 occasionally assumes a stellate form; Prof. Bennett has seen it 

 arranged in such a manner as strongly to resemble in appearance 

 an organic membrane. 



The triple phosphate, or ammonio-phosphate, of magnesia, 

 occurs in the form of triangular prisms, occasionally truncated, 



FJG. 421. 



FIG. 422. 



and sometimes with terminal facets. (Fig. 421.) If the urine be 

 very ammoniacal, they present a star-like or foliaceous appear- 

 ance (Fig. 422). Carbonate of lime is sometimes associated with 

 the earthy phosphates in human urine, but rarely in a crystalline 

 form. It generally appears in small round masses, or as an 

 amorphous powder. 



