118 ON THE PLACE OF FUSH IN 
lbs. ozs. grs. 
burns with a lilac flame. It occurs mainly 
as phosphate and chloride... A : oO 3 340 
12. Sodium, a metal, the basis of soda, and must be 
kept from the air. It occurs chiefly in union 
with chlorine as common salt, but also in 
other compounds and bile... a 2 © "3 217 
13. Magnesium—this metal is found in union with ~ 
phosphoric acid, mainly in bones .. ee 0 2.250 
14. Zron—this metal is essential to the colouring 
matter of the blood. It occurs everywhere 
in the body - at 5 a Sh 0 oO 63 
15. Manganese, a metal much like iron. Faint 
traces occur in the brain, and decided traces 
in the blood. 
16. Copper—traces of this metal are invariably found 
in the human brain, and probably also in the 
blood. 
Note to p. 29. 
It has been suggested that it is the instability— 
the readiness for change—of the nitrogen compounds 
which makes them so serviceable for hard work. All 
that can be said at present is, that though the facts 
as to their use seem clear, the explanation has not 
yet been satisfactorily arrived at. 
Note on Dr. E. Smith's popular form of putting the 
results of his work, p. 38. 
The following is an example of the way in which 
Dr. E. Smith illustrated that cost and economy in 
foods are different things. 
Two breakfasts are here selected for comparison, 
both of the same cost per head (14¢.) while one gives 
909 grains of carbon and 41 grains of nitrogen more 
than the other. 
