CHAP. V. THE ALBUMINOID RATIO. 989 



the same time so intelligible has elsewhere been written on the subject, 

 we have ventured to reproduce it here in its entirety. 



It will be noticed by the reader that Warington draws attention 

 to the important distinction between total nitrogenous matters and 

 true albuminoids in foods, and we may therefore explain that the 

 figures in the table of foods given on page 986 denote the percentages 

 of true albuminoids, and not of total nitrogenous matters. 



THE ALBUMINOID RATIO. " A progressing science is continually in 

 need of new terms. These new phrases, though necessary, are not 

 unfrequently a great stumbling block to persons who, although possess- 

 ing a good elementary knowledge of the facts of science, have been 

 unable to keep themselves posted up in modern scientific develop- 

 ments ; such persons are often baffled by new terms, although really 

 familiar with the facts to which these terms are applied. We will 

 commence, therefore, by stating what is meant by an ' albuminoid 

 ratio.' 



" The phrase ' albuminoid ratio ' was introduced some years ago by 

 myself, and is now pretty generally adopted by English writers. In 

 America the term employed is ' nutritive ratio.' The original German 

 phrase is ' Nahrstoffverhaltniss.' All these attempt to express the 

 same idea the ratio, or proportion, of the albuminoid to the non-albumi- 

 noid digestible constituents of food. If, therefore, we speak of barley as 

 having usually an albuminoid ratio of 1 : 8, we imply that when sheep or 

 oxen are fed with barley of average composition, the animal digests, 

 and receives into its system, eight parts of non-albuminous food for 

 every one part of albuminous food. 



" The idea attempted to be expressed by the ' albuminoid ratio ' of a 

 diet is thus a very simple one ; there are, however, several facts to be 

 borne in mind which somewhat complicate the subject. In the first 

 place, every food contains several non-albuminous constituents, and 

 these have not the same feeding value. The chief of these non- 

 albuminous constituents are fats, starch, sugars, and fibre. Of these 

 the fat is much the most valuable. 



" As the proportion in different foods varies extremely, being not more 

 that 2 per cent, in wheat or barley, and more than 15 per cent, in some 

 cakes, it is necessary in order to place different foods on the same 

 footing, to take into account this especially high value of fat. 



" It has been usual to reckon one of fat as equivalent to two and a 

 half of starch, and to assume that sugar and digestible fibre have the 

 same value as starch. The amount of fat has, therefore, been usually 

 multiplied by two and a half, and the product added to the sum of the 

 other non- albuminous constituents, the total thus representing the 

 whole of the non-albuminous constituents reckoned as starch. We 

 have, then, to bear in mind, that for the purpose of the albuminoid 

 ratio, the whole of the non- albuminoid constituents of any food are 

 reckoned as starch. 



" The method usually adopted is not, however, perfectly accurate. 



