256 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

 Composition and t'cilnations of various food materials. — German tables. 



318. Fuller details aud tables illustrating the principles liere presented, 

 may be found in a series of articles on science applied to farming, in 

 the "American Agriculturist" for 1874-'7G, aud in a lecture on " The Re- 

 sults of Late European Experiments on the Feeding of Cattle," in the 

 report of the Connecticut Board of Agriculture for 1874. A briefer 

 statement of the subject is given by Prof. S. W. Johnson in the report 

 of the Connecticut Agricultural Experiment Station for 1877. This 

 latter contains a table which is interesting as including, with German 

 analyses and valuations, some analyses of American products; with the 

 rest, two samples of fish-scrap. The table is explained by Professor 

 Johnson as fellows : 



"The following table of the composition, content of digestible nutri- 

 tive ingredients, and money value of a few of the most important feed- 

 iug-stulTs, is taken from the German of Dr. Emil Wolff, of the Agricul- 

 tural Academy at Hohenheim, and represents the most recent aud most 

 trustworthy knowledge on these subjects.* 



"The composition of feeding-stuffs, as here stated, is the average 

 result of the numerous analyses that have been made within twenty-five 

 years, mostly in the German experiment stations. 



"The quantities of digestible ingredients are partly derived from 

 actual feeding experiments and are partly the result of calculation and 

 comparison. 



"The percentages of the three classes of digestible matters, viz, al 

 buminoids, carbohj'drates, aud fat, form the basis for calculating the 

 money value of feeding-ptuffs. The values attached to them by Dr. 

 Wolff" are the following, the German mark being considered as equal to 

 24 cents, and the kilogram equal to 2.2 pounds avoirdupois : 



" 1 pound of digestible albuminoids is worth 4^ cents. 



" 1 pound of digestible fat is worth 4^ cents. 



" 1 i^ound of digestible carbohydrates is worth -f^ of a cent. 



"These figures express the present relative money values of the re- 

 spective food-elements in the German markets. Whether or not these 

 values are absolutely those of our markets, they represent i)resumably 

 the relative values of these elements approximately, and we may pro- 

 visionally employ them for the purpose of comparing together our feed- 

 ing-stuffs in respect to money value. These money or market values 

 are to a degree independent of the feeding values. That is, if of two 

 kinds of food, for example Hungarian hay and malt sprouts, the one 

 sums up a value of $0.6G and the other a value of 61.31 per hundred, it 

 does not follow that the latter is worth for all purposes of feeding twice 

 as much as the former, but it is meant that when both are i^roperly 

 used, one is worth twice as much money as the other. In fertilizers we 

 estimate the nitrogen of ammonia salts at 24 cents per i^ound, and solu- 



* From " Mcntzcl u. LengerJce's KaJender," for 1878. 



