CHEMICAL SCIENCE. 277 



common water for a drink, by which rather more than a grain of phosphate 

 of lime was ingested daily: on the other hand, a woman weighing 100 

 pounds enjoyed perfect health tipon a diet which furnished her daily with 

 90 grains of phosphate of lime thus health in the one case, and death in 

 the other, with relatively equal qiiantities of this salt. 



We shall recur to this example to show how complex are the conditions 

 of these experiments, and what reserve is necessary in drawing conclu- 

 sions from them. 



M. Mouries asserts, and the fact has already*- been noted by Chossat, that 

 if the proportion of alkaline phosphates of the food is deficient, there ensue 

 atony of the digestive organs, imperfect assimilation, and death. To prove 

 that pigeons die from want, of phosphate of lime, we may observe that 

 their death is hastened if they are allowed only distilled water, while their 

 lives may be preserved by adding earthy phosphates of their food. 



M. Bouchardat observed that the grain on which MM. Mouries and 

 Chossat fed their pigeons contained only traces of common salt. The birds 

 therefore should be expected to suffer from the deprivation of this principle. 

 M. Bouchardat accordingly made this experiment ; he confined two pigeons, 

 and fed them .on dried grain. In two months the health of the female 

 became impaired ; she suffered from thirst and diarrhoea, and laid no more 

 eggs. She was set at liberty. She flew immediately to a window- sill 

 impregnated with alkaline chlorides, and began to peck eagerly ; there was 

 a larger quantity of salts on the interior of the window frame ; the pigeon 

 entered through the open window, and permitted herself to be recaptured, 

 so imperious was her demand for these principles. Her health was rees- 

 tablished ; in three days she laid another egg. It is wrong, therefore, to 

 conclude, with M. Mouries, that a deficiency of phosphates is the only 

 cause of the symptoms he observed ; in this case, the absence of chlorides 

 was the obvious cause. 



M. Mouries has established, by interesting calculations, that grain fur- 

 nishes a sufficient supply of phosphate of lime for the reparation of bone, 

 but not for other essential functions of the economy. From the curious 

 fact that there is a constant proportion between the temperature of animals, 

 and the amount of phosphate of line contained in their blood, he deduces 

 the principle that this salt keeps up animal irritability, without which 

 nutrition is impossible. The following table presents some interesting facts 

 in physiology : 



Phos. Lime. Temperature. 



Blood of the Duck, 1.50 42 5 centigrade. 



" " Hen, 1.35 to 1.25 41 5 



" Pigeon, 1.20 1.23 40 " 



" " Man, 0.80 " 0.6 37 5 " 



" " Horse, 0.40 " 0.5 36 8 " 



" " Frogs, a trace, 9 " 



If these results are confirmed, it will appear that the ingestion of phos- 

 phate of lime is not only indispensable for the reparation of bone, but that 

 it is connected with the function of calorification. 



