2 Anatom. Museum, Berlin, 1796, vol. ii.
3 Arch. f. Path. Anat., vol. v.
The results of the pathologists and experimenters are confirmed by chemical analyses. Fat has been generally found somewhat increased in the rachitical bones, and water largely so; chondrin is diminished according to Marchand and Lehmann, but was found unaltered in the later analyses of A. Baginsky. The latter found, after having deprived the bone of fat, the organic and inorganic material to be in a proportion of 100 to 563 in the normal, and of 100 to 160 in the rachitical osseous tissue; and in 100 parts of dry bone, Gorup-Besanez found in the
| Ossein. | Phosphoric Acid. | Lime. | Manganese Oxide. | |
| Healthy adult | 34 | 26 | 34 | 0.3 |
| Infant of six months | 34.9 | 27 | 35 | 0.5 |
| Rachitical femur | 72 | 7 | 9 | 0.3 |
| Rachitical tibia | 60 | 12.9 | 17 | 0.3 |
Defective calcification of the forming bone is one of the principal characteristics of rachitis. In it lime cannot either enter into the composition of the osseous tissue or remain in it. Its elimination must take place either through the kidneys or the intestinal tract. In the feces Ad. Baginsky, and many before him, have found an abnormal quantity. In regard to the urine, modern investigations do not agree with former analyses. Thus, Baginsky concludes that there is no increase of lime in the urine of rachitical as compared with that of healthy children; Seemann found even a diminution of the percentage of lime. Amongst modern writers only Rehn found an occasional increase of lime in the urine of rachitis.
In regard to the elimination of phosphoric acid, the analyses of different periods do not agree any better. The conclusions of previous researches, pointing to a quadruple elimination of phosphoric acid in the urine of rachitis, are refuted by Seemann, who found no increase, and by Baginsky, according to whose researches the phosphoric acid of the healthy urine compares with that of rachitical urine as 40:12-37.
As far as the elimination of nitrogen is concerned, there appears to be but little difference between normal and rachitical urine. Chlorine was found to be diminished in rachitis by Baginsky. Lehmann and Von Gorup found lactic acid several times. Several times albumen was met with; in a case of Ritchie's, blood; in one of Von Gorup's, fat.4
4 E. Salkowski und W. Leube, Die Lehre vom Harn, 1882, p. 536.
The etiology of rachitis must be studied from two points of view. It has its predisposition and its direct and proximate causes. The former has been studied by F. W. Beneke5 upon an anatomical basis. He finds that the arteries of rachitical patients are large all through the body. This is so particularly in the carotids; it seems probable that the changes taking place in the head are due to this anomaly in the size of the arteries. Three cases in which the width of the arteries of the neck was unusually large terminated fatally—one by hydrocephalus, one with a very large skull, and one suddenly. This width of the arteries is most marked, under ordinary circumstances, from the second to the fourth year; that is, the exact time in which (except the cases of early rachitis) the rachitical process is at its height. It is considered by Beneke to be the cause of the local increase of vascular irritation, particularly in the epiphyses with their retarded circulation; and also of the increase of nutritive development which is so often noticed during recovery from rachitis; and, finally, of the many pulmonary complications of an inflammatory nature.
5 Die Anatomischen Grundlagen der Constitutions Anomalien des Menschen, 1878, p. 75, etc.