No. C. DEPARTMENT 01' A( lltK 'IIJ.TIIRE. KIty 



affoided by exlenial npix'arjmce or simple physii-al tcsl of the* ex- 

 ti'ut nor evou in many cases of tlie dircclion in which a partinilar 

 h)t of any 54iven material will depart in composition from tlie aveia^^e 

 feed if its kind. \\ lien all extei-nal (lualilies indicate that the feed 

 is of good grade, the tendency, nnder conditions of strong competi- 

 tion, is U) oiler a gnaranty high for goods of its class; but because 

 appearances are often deceptive, the wise rule is to yuarantee tice 

 presence of no larger quantity of the i<everal valuable uiyredientx 

 that one niay^ with fair certainty^ assume to he present. This rule 

 does not re(iuire that the guaranty shall be no higher than the low- 

 est ever found for the kind of material in question, because these ex- 

 treme figures usually attend some abnormality of growth or de- 

 velopment; the rule would indicate, however, that for the purposes 

 of guaranty, in the absence of the specific knowledge concerning the 

 composition of the lot of goods employed which their analysis would 

 afford, some figure between the average and the lowest should be 

 chosen. To illustrate, the percentages of protein and fat given in the 

 table for common, yellow dent corn are: 



Lowest, 



Highest. 



Average, 



A great many samples of corn that appear to be of at least aver- 

 age quality, contain less than 10 per cent, of protein and 5 per cent, 

 of fat. The percentage midway between the lowest and the average, 

 that is, \) per cent, for protein and 4 per cent, for fat, are the high- 

 est that can safely be adopted for guaranty in the absence of di- 

 rect analysis of the goods in hand for use in any given mixture. 



2. 2o calculate the composition^ for purposes of guaranty, of a mix- 

 ture of feeding- stuffs^ ichen the compositions and quantities of each in- 

 gredient of the mixture are kno'wn : 



Kule. In the case of each constituent required to be included in the 

 guaranty, determine the number of pounds of it wiiich each ingredi- 

 ent of the mixture supplies; this is done by mulliiilying the guar- 

 anty percentage of the constituent in each ingredient by the number 

 of hundredweight of the latter used in the mixture. Next, ascer- 

 tain the total amount of the constituent in the mixture by adding 

 the amounts of it supplied by the several ingredients used. Finally, 

 divide the sum thus obtained, by the number of hundredweights of 

 the entire mixture; the result of this division is the guaranty per- 

 centage of this particular constituent for the entire mixture. 

 56 



