468 CALCIFICATION, CONCRETIONS, AND INCRUSTATIONS 



Lung stones.*^ — These may be formed in the bronchi, through accretion about 

 an inorganic nucleus, similar to the formation of calculi in other epithelial-lined 

 passages; or they may consist of calcified areas of lung tissue or peribronchial 

 glands, which have been sequestrated 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 represent calcified 

 tubercles is shown by Stern" and by Biirgi." who demonstrated tubercle bacilli 

 in decalcified lung stones. The following percentage figures are taken from Ott:*' 



Calcium phosphate 52 . 72 . 8 



Magnesium phosphate 1.0 



Magnesium carbonate 2.0 



Calcium carbonate 13 6.0 



Fat and cholesterol 24 . 7.0 



Other organic substances 4.0 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 ; 



Tonsillar concretions consist chiefly of carbonate and phosphate of calcium 

 deposited upon the inspissated secretions and desquamated cells of the tonsillar 

 crypts.^" According to some authors, leptothrix threads frequently form the 

 nucleus of the concretions. 



Cutaneous concretions are occasionally observed, located chiefly in the sub- 

 cutaneous tissue, often occurring multiple. The origin is possibly in dilated 

 sebaceous glands with retained secretions. Unna considers that calcium soaps are 

 formed as a first step, but an analysis of such material bj' Harley^^ showed 87.2 

 per cent, of ash, 12.8 per cent, organic matter, 0.9 per cent, of fat; calcium phos- 

 phate constituted 65.2 per cent., and calcium carbonate 16.4 per cent. Gascard^^ 

 found in similar material 23.4 per cent, organic matter, and of the inorganic matter, 

 91.1 per cent, was calcium phosphate, and 8.9 per cent, calcium carbonate. 



Gouty deposits observed in the subcutaneous tissues, as well as along the 

 tendons, articular cartilages, etc., consist usually of nearly pure biurate of sodium 

 and potassium. Ebstein and Sprague^^ found the composition of such material to 

 be as follows : 



Uric acid 59 . 70 



Tissue organic matter 27 . 88 



Sodium oxide 9 . 30 



Potassium oxide 2 . 95 



Calcium oxide 0.17 



MgO, Fe, P2O6, S traces 



"Literature. Poulalion, Thesis, Paris, 1891; Stern, Deut. mcd. Woch., 1904, 

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

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



*'' "Chem. Path, der Tuberc," 1903, p. 92. 



■»8 Literature, Scheppegroll, Jour. Amer. Mcd. Assoc, 1896 (20), 874; Gcrber, 

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



*^ Jour. Pluirm. et Chiin., 1891 (23), 447. 



^"McCarthy, Brit.Med. Jour., Oct. 28, 1911. 



''' Jour. Pliarm. et Chim., 1903 (18), 9. 



»2 Ibid., 1900 (12), 262. 



" Virchow's Arch., 1891 (125), 207. 



