33') 



A TEXTBOOK OF PHYSIOLot.y 



and use this for salt. During salt starvation the amount of chlorine 

 in the iirine constantly decreases, so that eventually the excretion of 

 chlorine may stop. 



Lack of Alkali Carbonates. If the alkaline bases be withheld, there 

 ensues an acid intoxication of the body, and life thus endangered. 



Lack of Phosphates. Lack of phosphates may seriously impair 

 the bodily functions. The bony tissues are particularly affected. 

 It is a question as to how far lack of phosphates affects the formation 

 within the body of phosphorized compounds such as phosphoprotein, 

 and of phosphorized fats such as lecithin. The available evidence 

 seems to show that these bodies can be synthesized from organic 

 bodies poor in phosphorus and inorganic phosphates. 



Lack of Iron. Iron is of great importance to the organism, since 

 it is contained in the blood-pigment, haemoglobin, and also in the 

 nuclei of cells. It is necessary, too, for the oxidative processes 

 initiated by oxidases. Lack of iron leads to anaemia, insufficient 

 nutrition, and eventually to death. 



Although debated, it seems probable that iron may be utilized 

 when ingested in either organic or inorganic form. Iron is introduced 

 into the body by various foodstuffs. This can be seen from the fol- 

 lowing table, which shows the amount of iron in milligrammes in 

 100 grammes of dried substance: 



White of egg . 

 Rice . . 

 Wheat flour . 

 Milk .. 

 Peas . . 

 Potatoes 



trace 

 1-2 

 1-6 

 2-3 



6-2 

 6-4 



Carrots 



Apples 



Cabbage 



Beef 



Yolk of egg 



Spinach 



8-0 

 13 

 17 

 17 



10-24 

 33-39 



Lack of Carbohydrates and Fats. The result of withdrawing fats 

 and carbohydrates from the diet depends on the class of animal. 

 Carnivora can live for a long time on a diet consisting, as nearly as 

 possible, of protein only, viz., lean meat freed from as much fat as 

 possible. Omnivora or herbivora do not appear to be able to live on 

 such a diet. The replacement of fat by excess of carbohydrate leads 

 to the retention of water in the body. Fat starvation causes a form of 

 dropsy. The food eaten per diem should contain at least 60 grms. 

 of fat 



Lack of Lipoids. There is some evidence that these may be 

 synthesized in the body out of protein and carbohydrate. They are 

 essential, and it is advisable that they should be in the diet. 



Lack of Vitamines. The fresh foods contain certain active prin- 

 ciples necessary for nutrition and growth, which may be removed by 

 the modern processes of milling or canning food. If these are in- 

 sufficient nutrition is gravely affected. 



The first knowledge of the effect of a deficit of these bodies was 

 afforded by the study of the disease known as beri-beri. It is now 

 conclusively shown that this disease is due to feeding (as the almost 

 sole article of diet) on " polished " rice that is to say, rice from which 



