DIETKTIC 1)I:KIC1KN(. ^^ 2gi 



At the ct)ninKnceineut of feeding, three pigs on Diet I 

 together weighed i/./ l<gs., and three pigs on Diet 2 weighed 

 17.6 kgs. Six months later the total weights were 41.8 kgs. 

 and 36. <S kgs. respective!}- — i.e.. the pigs on the diet to which chalk 

 had heen added had gained 135 per cent, as against no per cent, 

 for those on the calcium-poor ration, the quantity of food eaten 

 being the same in each case. Dried blood was then substituted 

 for gluten meal ( leaving the calcium content practically unal- 

 tered), and the pigs weighed separately. .\t this time pig No. i, 

 on the calcium-rich diet, weighed 17.9 kgs.. and pig No. 4, on the 

 calcium-i)()()r diet. 13.5 kgs. Three months later No. i weighed 

 35.7 kgs., i.e., i)racticaily double. Pig No. 4. on the other hand, 

 decreased in weight to 12.6 kgs.. steadily losing appetite and 

 refusing to eat an adequate amount of food. The animals were 

 then killed, and their bones analysed : — 



Pig Xo. I. Pig No. 4. 



Character of bones Xnrmal Thin, deformed, soft 



flexible. 

 Weight of fresh Skeleton .. -2.675 kgs. 1.612 kgs. 

 Weight of fat-free dry skele- 

 ton 1 . 198 kgs. 0.592 kgs. 



Water content of skeleton.. 46.59 per cent. 57-41 per cent. 

 Mineral matter of fat- free 



drj- skeleton 48-40 per cent. 40.03 per cent. 



Lime in fat-free dry l>ones — 



Skull .i,?i4 per cent. 30.01 per cent. 



Ribs 23.75 per cent. 13.88 per cent. 



Fore-legs -^5-21 per cent. 18.87 P<?r cent. 



From these figttres it is seen that on the calcitmi-deticient 

 diet the aniiuals suffered in general health and failed to grow 

 normally, more especially in the later stages of the experiment. 

 The growth of bone was notable restricted and calcification was 

 defective. The simple addition, in the form of chalk, of the 

 missing calcium sufficed to allow of comparatively normal deve- 

 lopment. 



The deficiency here may. in the nio.in, be regarded as of a 

 relatively simple kind. The calcium salts actually required for 

 normal metabolism are absent from the food, and calcium-starva- 

 tion ensues, bringing with it not merely a pathological condition of 

 the bones where the demand for calcium is highest, but also a 

 general disturbance of bodily function and development Where 

 deficiency in lime is less acute it may perhaps happen that the 

 only serious disturbance is that of bone metabolism, llie con- 

 verse case, however, by no means holds. Thus a general mal- 

 formation and defective calcification of the bones does not neces- 

 sarily indicate a deficiency of calcium in the diet. As illustrating 

 this we have the two diseases osteomalacia and rickets, both of 

 which are associated with defective bone structure, and yet both 

 of which may occur on diets containing a large excess of calcium 

 compounds. In such cases the pathological condition of the bones 

 is an eflect of the di,3ease, whereas in the former case of calcium- 

 starvation the dietetic deficiencv is the cause. This distinction 



