456 ON THE PLACE OF FISH IN 



AN EASY WAY TO CALCULATE THE NUMBER OF GRAINS OF 

 NITROGEN PRESENT IN DIFFERENT WEIGHTS OF NITRO- 

 GENOUS COMPOUNDS. 



Though fractions of a grain are important in a chemical 

 analysis it is near enough in practical dieting to be within 

 i of an ounce. The daily range of nitrogenous compounds 

 taken is between 4 and 5^ ounces. 



Calculate 438 gr. to oz. ; 219 to J oz. ; no to i oz. (near 

 enough). For ready reference expressed in grains 



4 oz. = 1752 gr. ; 4^ oz. = 1862 gr. ; 4^ oz. = 1971 gr. ; 

 4} oz. = 2081 gr. ; 5 oz. = 2190 gr. ; 5^ oz. = 2300 gr. ; 

 5J oz. = 2409 gr. (more exact than 2410). 



If the analyses of various nitrogen compounds is ex- 

 amined it will be seen that about 15 J or 16 parts per 

 hundred (three examples of which are given on p. 357) 

 are nitrogen. This is so uniformly the case in all analyses 

 that for the convenience of calculation without analysis 

 1 6 parts in the hundred of any nitrogenous compound are 

 taken as nitrogen. In making calculations in grains every 

 100 grains of a nitrogenous compound is taken to contain 

 1 6 grains of nitrogen, every 50 contains 8, every 25 con- 

 tains 4, and so on. 



Beginning at the 4 oz., that is 1752 grains, there are 17 

 hundreds (17 times 16= 272) and one fifty (=8 grains N), 

 and the odd 2 may be omitted; so 1752 grains of nitrogen 

 compound contain 272+8= 280 grains of nitrogen. 

 Working out this way or any other more convenient, the 

 results come : 



Nitrogenous 



4 or expressed in grains . 1752 contain . , 280 

 4j . 1862 . . 298 

 4J 1971 . . 314 

 4f 2081 . . 333 



5 2190 . . 350 

 5 . 2300 . . 368 

 5 2409 . . 385 



This can, of course, be worked the reverse way. Suppos- 

 ing a diet is wanted to contain 350 grains of nitrogen, then 

 5 ounces of some nitrogen compound must be taken. 



