206 



THE COMPLETE GRAZIER. 



BOOK I. 



instead of Herefords, and with eight animals in each set. The trial 

 occupied 120 days, the results being : 



Grain per head per day with Decorticated Cotton-cake . . . 2 '38 Ib. 



,, ,, Undecorticated Cotton-cake . . . 1'84 ,, 



Rape-Cake is less relished by cattle than linseed-cake, and they require 

 to be coaxed into partaking of it ; once habituated to it, they consume it 

 freely. Dr. Voelcker says he believes " the pungent principle in rape-cake 

 arises from the presence of mustard-seed, which is often contained in 

 considerable quantities in foreign rape-cake. Mustard and rape-seed 

 belong to the same family of plants ; and in Germany, at least, I am 

 sorry to say, our rape-fields are often very foul with mustard. That 

 boiling water prevents the pungent acrid smell is fully explained by 

 the chemistry of mustard-seed. That seed does not contain any 

 volatile or essential oil of mustard, the cause of the pungency of 

 mustard taste ; but it does contain two peculiar principles, which, in 

 contact with cold or tepid water, generate essential oil of mustard the 

 one is called by chemists ' myronic acid,' the other ' myron.' The 

 latter is a substance like albumin, and, when moistened with cold water, 

 acts as a kind of ferment upon myronic acid, producing the acrid oil of 

 mustard ; whereas boiling water coagulates myron like albumin. In a 

 coagulated state myron loses its efficacy as a ferment, and consequently 

 no pungent or acrid smell is produced when cake containing mustard 

 is mixed in boiling water. . . However, the practical result of mix- 

 ing rape-cake with boiling water deserves to be generally known, for 

 even pure mustard-cake will lose its poisonous character or, more 

 correctly, its poisonous qualities will not be called into existence if it 

 be mixed with water at the temperature of 212 Fahr." 



While on the subject of oil-cakes, it will be interesting and instructive 

 to give here a resume of the experiments of Crusius, to determine the 

 influence of the oily matters in food on the fattening of stock : for this, 

 with the accompanying remarks, we are indebted to the pages of the 

 " Scottish Farmer ": 



" For this purpose twelve oxen, as nearly similar as possible, were 

 selected and divided into two series of six each. These were supplied 

 with mixtures of different foods, so adjusted as to contain as nearly as 

 possible the same quantities of dry matter, nitrogenous compounds, 



TABLE SHOWING THE DAILY QUANTITY OF FOOD GIVEN TO THE 

 SIX OXEN OF EACH SERIES. 



