COMPOUNDING RATIONS 237 



DE be now measured it will be found that they stand in the 

 ratio of 3*24 to i, i.e. in the proportions in which the foods 

 must be used to give an N-ratio of 6 to i. 



N.B. The proportions must be taken inversely 3*24 parts 

 of rice meal to i of linseed cake. 



This is one of the quickest and easiest methods of finding 



Protein 

 60 'i 



4-0 



30 



N 



20 



10 



10 20 30 4-0 50 eo 7O so 90 too"Starch" 



per cent. 



FIG. 16. 



the relative proportions in which two foods must be combined 

 to give any specified N-ratio. It can be readily applied even 

 by those who do not understand the principles on which it is 

 based. All that is necessary is to mark the positions of the 

 two foods on a piece of squared paper, join the two points, 

 and then draw the ratio line of the specified dietary. If these 

 two lines intersect, the lengths of the parts AD and DE can 

 be measured off with a pair of compasses with sufficient 

 accuracy for practical purposes. If the two lines do not 

 intersect, the specified N-ratio cannot be produced by any 

 combination of the two foods in question. 



Cor. i. The point D is the position, on the chart, of a 



