.38 DIGESTION AND FOOD. 



into a mourning ring, which they wear in memory of their 

 dead friends. Here, then, we have a very conclusive proof 

 that iron really exists in the human body." 



The circumstance here referred to cannot apply to any 

 regular practice, because the French bury their dead as we 

 do; still, in evidence of obtaining a certain quantity of iron 

 from blood, I may mention that a Paris physician used to 

 wear a little iron ball on his watch-guard composed of iron 

 obtained from human blood. He must have laboured hard 

 to obtain a sufficient quantity, as the amount of iron in blood 

 is not very great. Poggiale found in 1000 parts the following 

 proportions in man and animals : 



Man, , . . 1-26 

 Ox .... 1-25 

 Cow. , . . 1-43 

 Calf. . . .1-11 

 Dog . . , .1-45 



Cat , . . . 1-23 



Sheep , . .1-06 



Eabbit . j . 0-97 



Hen . , . . 075 



Pigeon . , . 0-62 



Iron, as an element of the ;animal frame, ranks in impor- 

 tance with common salt and phosphate of lime; and, as 

 Liebig says, u It is quite certain that if iron be excluded 

 from food, organic life cannot be supported." 



Manganese is another metal supposed by some essential to 

 the integrity of many animal structures. It is an ingredient 

 of Scotch soil, and hence through plants finds its way into 

 Scotch blood and muscle; but manganese cannot be regarded 

 in the same light as iron. It is not essential to life. 



Lehmann refers to proximate principles of animals and 

 vegetables, which he calls accidental mineral substances. He 

 mentions, under this head alkaline sulphates, carbonate of 

 magnesia, manganese, arsenic, copper, lead, ammoniacal salts, 

 and sulphocyanide of sodium. 



Alkaline sulphates, except in the bones of reptiles and 

 fishes, do not exist as such except in rare instances, and 



