378 LECTURE XVI. 



by observations of the metabolism which takes place during the disease. 

 Thus Goldthwait, Painter, Osgood, and McCrudden l found that when the 

 nourishment contained 4.56 grams of lime there was an elimination of 3.859 

 grams by the urine and of 1.80 grams by the faeces. Thus the organism 

 lost 1.10 grams of lime in the process. Hand in hand with the decalcifi- 

 cation, a formation of an organic substance takes place. This substance is 

 characterized by a high sulphur and a low phosphorus content. Curiously 

 enough, while the calcium is being carried away from the organism, mag- 

 nesium is being held back. Considering all these facts together, we are 

 led to the conclusion that the disease is not caused by a giving up of lime 

 to the organism of the child, but that evidently there is a severe metabolic 

 disturbance of the bony tissue which naturally must be influenced indi- 

 rectly by the important transformations which are taking place in the entire 

 metabolism of the organism of the mother due to the presence of the 

 new being. But just as in the disease of richitis the lime plays a more or 

 less passive part, it is indeed highly probable that here again the absence of 

 lime is not directly responsible for the trouble, but that the loss of lime 

 takes place secondarily as a result of the disease. The lime is loosened 

 from its state of combination in the bones, and is eliminated as refuse out 

 of the system. The primary trouble is a disturbance in the economy of 

 the bony tissue. It has been frequently suggested that the cause of the 

 decalcification is due to the appearance of acids. This was deduced from 

 the fact that lactic acid is found in the urine of those suffering from osteoma- 

 lacia. The appearance of the lactic acid, however, does not prove anything 

 in this direction. In fact, cases of the disease are known in which no lactic 

 acid could be detected in the urine; and we know, furthermore, that the 

 acid may appear in the urine for quite a number of different reasons with- 

 out the lime-content of the bones being affected at all. The appearance 

 of lactic acid in the urine does not indicate where the acid originates. 

 There is absolutely no foundation for the assumption that the acid in 

 osteomalacia is formed in the bony tissues and serves to dissolve out the 

 lime. 2 



Fehling's 3 observation, that removal of the ovaries serves to check the 

 disease, has shed a peculiar light upon the nature of the disease. After 

 this operation, lime is once more retained by the system, and the newly 

 formed osteoidal tissue calcines. At present we can merely assume that 

 the loss of the ovaries brings back the metabolism to normal paths. We 



1 Am. J. Physiol. 14, 389 (1905). 



2 Cf. C. Schmidt, Ann. 6l, 329 (1847). Moers and Muck, Deut. Arch. klin. Med. 

 6, 485 (1869). Nencki and Sieber, J. pr. Chem. 26, 43 (1882). M. Levy, Z. physiol. 

 Chem. 19, 239 (1894). 



3 Arch. Gynak. 39, 171 (1891); 48, 472 (1895). Cf. also Winckel: Sammlung klini- 

 scher Vortrage N. F. No. 71. 



