Etiology. 933 



barley feed flour, 0.7 (10.8). Waste from sugar factories— Beet-chi-ps, 1.1 (0.2); 

 beet treacle, 3.1 (0,5). Waste from oil mills — Linseed cake, 4.3 (16.2); rape seed 

 cake, 7.1 (20.0) ; ground-nut cake, 1.6 (11.6). Animal food stuffs — Meat (without 

 bone), 0.3 (4.2); ground meat flour, 3.6 (6.9). Of the lime contained in vegetable 

 food stuffs at most one-half is made use of (Kellner). 



Calcium requirements of growing animals. According to C. Voit the calcium 

 requirement in growing dogs of smaller breeds, weighing 1.5-2.8 kg. is 0.128 gm. 

 daily; in dogs of large breeds (weight 3.2-4.5 kg.) 0.769 gm. daily; in pigs 1-240 

 days old 2.8 gm.; in pigs over 8 months old 1.7 gm.; calves require in the second 

 or third week 14.5 gm. daily, in the fifth month 13.3 gm. (Lehmann), one-year olda 

 require 21 gm. of lime (Kellner). In lambs the calcium requirement for 50 kg. 

 body weight is, according to Weiske, as follows: In the first month, 3.2 gm. ; 

 at 5.5 months, 3.8 gm. ; at 8.5 months, 3.2 gm. ; at 11.5 months, 2.7 gm., while 

 in the 16th month of their lives they require only 0.6 gm. of lime. 



The injurious effect of food wliicli is deficient in lime was 

 proved by numerous animal experiments. 



Chossat (1842), Milne-Edwards (1861), Guerin (1862), Eoloff (1866), E. 

 Voit (1877), Lehmann (1877), Baginsky (1881), and recently Miwa & Stoeltzner 

 succeeded in producing a clinical picture which was in its symptoms and in its 

 gross pathology quite similar to rachitis in young pigs and dogs that is due to 

 food containing very little calcium. In these experiments they observed swelling 

 of the epiphyses, softening and various curvatures of the bones, while other authors, 

 especially Weiske and Wildt (1873), Tripier (1874), Piitz (1875), Delcourt (1899) 

 failed to cause the disease in this manner. The cause of their failure may lie on 

 the one hand in the too short duration of the experiments, on the other, and 

 mainly, it was probably to be found in a very far-reaching withdrawal of lime 

 or of all nutritive salts. It must, however, be admitted that in most of the positive 

 results cited the proof of the rachitic nature in the anatomical changes was not 

 afforded by microscopical examination; only E. Voit and Baginsky described his- 

 tological changes which corresponded with those found in rickets. Neither Miwa 

 & Stoeltzner, nor Eeimer & Boye were able to demonstrate such tissue changes in 

 their experiment animals which appeared clinically to be rachitic, as would have 

 agreed with those found in true rachitis. (For the interpretation of their results 

 see Pathogenesis.) 



Miwa & Stoeltzner observed in a dog that was fed with fresh horse meat and 

 bacon, and received distilled water to drink, a waddling walk as early as the 10th 

 day, and a moderate epiphyseal swelling on the fore-feet was apparent already 10 

 days later. At the end of the fourth week the dog disliked to move about, or 

 crouched down, whining after taking only a few steps; nor was he able to climb 

 upstairs. The swelling of the epiphyses gradually increased, on the distal ends of 

 the ribs strongly prominent enlargements became noticeable, which were arranged 

 in rosary fashion, while the long bones were bent outwards. The motor disturb- 

 ances did not continue to progress from the seventh week on, and the dog was 

 killed at the end of the eighth week. At the autopsy the authors found the compact 

 portion of the bones forming a network of wide-meshed bone lamellae and hollow 

 spaces of different sizes; the cambium layer of the periosteum was enlarged; 

 periosteal osteophytes were on the enehondral zones of ossification between epiph- 

 ysis and diaphysis; the lines of ossification were rather irregular; the layer of 

 "proliferating cartilage extended ; the columnae of cartilage cells in irregular arrange- 

 ment and the cartilage cells themselves enlarged. The preliminary calcification of 

 cartilage was, however, quite normal, as was also the bony substance which con- 

 tains no lime, and which surrounds the lime-containing bony lamellae everywhere 

 in very delicate traceries. In contrast to this autopsy result in place of the 

 normal delicate deposits which contain no lime, there were found in true rachitis 

 thick plates of tissue entirely without lime which surround on all sides the lime- 

 containing portions or which, in very severe cases, replace a considerable portion 

 of the bony lamellae. A further distinction from rachitis was found in the normal 

 zone of ossifying cartilage. Therefore the authors explain the process as a gen- 

 eralized osteoporosis with rachitis-like changes in the periosteum and in the uncalci- 

 fied proliferating cartilage, and they suggest that the bony changes observed after 

 withdrawal of lime by other authors had been similar to theirs. 



In the experiments of Eeimers & Boye and of Getting the compact bone 

 substance was found very small, the spongiosa with extremely wide meshes; the 

 extension of the proliferating cartilage was only slight, a proliferation of the osteoid 

 tissue had not taken place at all. 



