l'()l!M\n<)\ OF CM.illU SOM'S 441 



ated area, soon loading to a sliell of inorganic material which would 

 limit the deposition. 



The possibility of the formation of calcium-binding substances 

 within the degenerated area has always seemed the most attractive, 

 and has received the most attention by investigators. Of the special 

 substances that might be present in such areas that would have a 

 high afifinity for calcium, phosphoric acid usually receives first con- 

 sideration, since it is as phos])hate tliat most of the calcium is bound, 

 and also since the possible sources of phosphoric acid in decomposed 

 nucleoproteins and lecithin are so obvious. Less considered in the 

 past, fatty acids offer another possibility, especially in view of the 

 fatty degeneration that so frequently precedes calcification. Proteins 

 might also be formed that Avould combine calcium, especially deutero- 

 albumose, which Croftan ^^ states has a high degree of affinity for 

 calcium, and which would be present in areas undergoing autoly- 

 sis. 



Formation of Calcium Soaps. — In favor of the possibility that 

 the calcium is first bound as soaps are the following facts : Calcifica- 

 tion occurs chiefly in places where fatty degeneration has occurred, 

 such as tubercles, atheromatous vessels, etc. In fat necrosis fatty 

 acids are formed, which soon combine with calcium to form calcium 

 soaps. Virchow observed calcification in the form of soaps in a 

 lipoma, and Jaeckle ^* found that a calcifying lipoma contained 29.5 

 per cent, of its calcium in the form of calcium soaps. Klotz ^^ ob- 

 tained staining reactions in calcifying tissues that suggested the pres- 

 ence of soaps, which he also extracted by solvents, and he strongly 

 urges, as the first step in the formation of pathological calcified 

 masses, that the calcium is first laid down as soaps, afterward under- 

 going a transformation into the less soluble phosphate and carbonate. 

 Fischler and Gross -" also obtained microchemical reactions for soaps 

 in the margins of infarcts and in atheromatous areas, but not in 

 caseous areas; they therefore consider that calcium-soap formation is 

 an important step in the process of pathological calcification, but 

 that it is not essential. The value and the interpretation of the his- 

 tological evidence of the participation of calcium soaps is, however, 

 open to question. 



On the other hand, Wells,-^ studying large quantities of material 

 chemically, found at most doubtful traces of calcium soaps in calci- 

 fying matter, even in the earliest stages, and also very small amounts 

 of other soaps or fatty acids, and, therefore, questions the occurrence 

 of calcium soaps as an essential step in calcification, although not 

 doubting that under certain conditions (e. g., calcifying lipomas, fat 



I'.Tour. of Tuberculosis. in03 (5), 22. 

 isZeit. physiol. Chem., inn2 (36). .53. 



19 Jour. Exper. :Nred., ion.5 (7), 633; 1906 (S), 322. 



20 Ziegler's Beitr., 1005 (7th suppl.). 339. 



21 See review in Arch. Int. Med., 1911 (7), 721. 



