STATISTICS OF NUTRITION. 679 



A dog weighing thirt}'-two kilos, which experience showed could 

 be kept in constant weight by receiving six hundred to seven hundred 

 grammes meat and one hundred and fifty grammes fat, was allowed to 

 eat as much as he would take of the above foods, and 3 r et he rapidly 

 commenced to fail, and in fourteen days was unable to stand from his 

 great weakness. After three weeks disturbance of digestion appeared 

 indigestion, diarrhoea, and finally vomiting. 



The comparison of the inorganic income and outgo showed that, as 

 regards phosphoric acid, 21.9 grammes were taken in while 51. 7 grammes 

 were excreted; consequently, the dog had lost 29.8 grammes of phos- 

 phoric acid, or ten times the amount which is normally contained in the 

 blood ; 7.24 grammes of NaCl were lost. 



These results show that the body cannot be sustained by organic 

 substances alone, but must also receive a certain amount of inorganic 

 salts. If the amount of salts in the food sinks below a certain figure 

 or is entirely suspended, salts are excreted by the economy, and the 

 body passes into such a state of malnutrition that death speedily results. 



As regards the amount of inorganic salts required by different 

 animals in order to preserve perfect nutrition, it appears that the 

 amount of NaCl in meat, which amounts to 0.11 per cent., is sufficient 

 for the needs of the carnivorous animal. As a consequence, these ani- 

 mals prefer unsalted to artificially salted foods. 



It is quite different with the herbivora, for, although these animals, 

 as a rule, receive proportionately quite as much salt in their food as the 

 carnivora, they will, nevertheless, always greedily devour salt. 



As regards the relative proportion of these salts required by different 

 animals, it appears that all animals require relatively similar propor- 

 tions of chlorine and sodium, but that herbivora take in their daily 

 food at least double as much potassium as carnivora. 



Thus: One kilogramme cat, fed with mice, takes daily 0.1434 

 gramme K, 0.0743 Na, 0.0652 Cl! One kilo ox, fed solely with clover- 

 hay, 0.3575 gramme K, 0.0266 Na, 0.0433 Cl ; when fed with beet-roots 

 and oat-straw, 0.2923 gramme K, 0.0674 Na, and 0.0603 Cl. 



The following table gives the amounts of K, Na, and Cl in various 

 foods : 



