464 



CALCIFICATION, CONCRETIOyS, AND IXCRUSTATIOyS 



soaps, incrusted with inorganic substances, of which ammonio-magne- 



sium phosphate and calcium phospliate are usually the most abundant. 



Prostatic concretions originate in the corpora amylacea through 



growth accretion of inorganic salts, until they may reach considerable 



size. Stern " gives the following results of analysis of such a prostatic 



stone : 



Water 8.0 



Organic matter 15-8 



Lime 37.64 



Magnesia 2.38 



Soda 1-76 



Potash 0.5 



Phosphoric acid 33.77 



Iron trace 



Lung stones.' 1 — These may be formed in the bronchi, through ac- 

 cretion about an inorganic nucleus, similar to the formation of cal- 

 culi in other epithelial-lined passages ; or they may consist of calcified 

 areas of lung tissue or peribronchial glands, which have been se- 

 questrated through suppuration and have entered the bronchi. In 

 the latter case, the calculi present the usual composition of patho- 

 logical calcified areas. That the expectorated stones frequently rep- 

 resent calcified tubercles is shown by Stern ^^ and by Biirgi,^^ who 

 demonstrated tubercle bacilli in decalcified lung stones. The follow- 

 ing percentage figures are taken from Ott : ^- 



Calcium phosphate 52.0 72.8 



]\Iagnesiimi phosphate 

 Magnesium carbonate 



1.0 



2.0 



Calcium carbonate 13.0 



Fat and cholesterol 24.0 



Other organic substances 4.0 



6.0 



7.0 



10.0 



Rhinoliths " are formed about nasal secretions, blood-clots, and 

 most frequently about foreign bodies. They therefore contain much 

 organic substance in addition to the inorganic salts deposited upon 

 them. Berlioz ^^ gives the following table from the analysis of four 

 specimens : 



loAmer. Jour. Med. Sci., 1903 (126), 281. 



11 Literature. Poulalion. Thesis, Paris, 1891; Stern, Deut. med. Woch., 1904 

 (30), 1414. Biirgi (Deut. med. Woch., 1906 (32), 798); Gerhartz and Strigel, 

 Beitr. z. klin. Tuberc, 1908 (10), 33. 



i2"Chem. Path, der Tuberc." 1903, p. 92. 



13 Literature, Schc))pegrell, Jour. Amer. Med. Assoc, 1S9C (20), 874; Gerber, 

 Deut. med. Woch., 1892 (18), 1165. 



"Jour. Pharm. et Chim., 1891 (23), 447. 



