On Pulping Roots for Cattle Food. 
457 
the smell on different days while using the same cake, and also 
simultaneously in the appetite of the animals for their feed. It 
was soon perceived that this did not happen on those occasions 
on which the process of dissolving the cake had been continued 
beyond the hoilinfj-point. We thought this an interesting fact, 
and that it would be desirable to ascertain the cause of this, as 
the investigation might lead to further information as to the 
composition of the cake. We therefore mentioned the circum- 
stances to Dr. Voelcker at the time, who, after a careful exami- 
nation of the subject, sent us, in the spring of 1855, the following 
very interesting Report : — 
" I believe the pungent princijilc in rape-cake arises from the presence of 
mustard-seed, which is often contained in considerable quantities in foreign 
rape-cake. Mustard and rape 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 
miistard. 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 
' mjTonic acid,' the other ' myron.' The latter is a sirbstance like albumen, and 
when moistened with cold water acts as a kind of ferment upon myronic acid, 
producing the acrid oil of mustard ; w^hereas boiling water coagulates m3Ton 
like albumen. In a coagulated state myrou loses its efficacy as a ferment, and 
consequently no pungent or acrid smell is produced when cake containing 
mustard is mixed in boiling water. I am not aware that clean rape-seed con- 
tains analogous principles to tliose in mustard ; but, as this is possible, 1 shall 
be glad if you will send me a few ounces of decidedly clean rape-seed. A few 
experiments with such rape-seed will soon lell me if it contains substances 
allied to myronic aciel and myron in mustard-seed, or if (which I expect 
to be the case) your rape-cake is made from seed coutainiug a mixture of 
mustard-seed. 
" However, the practical result of mixing rape-cake with boiling water 
deserves to be generally known, for even pure mustard-cake will lose its 
poisonous character — or, more correctly speaking, its poisonous qualities will 
not be called into existence — if it be mixed with water at the temperature of 
212° Fahrenheit. 
" An analogous case is presented to us in bitter almonds. There the albu- 
minous substance which acts as a ferment in contact with water is called 
' emulsin.' Besides this emulsin, bitter almonds contain a beautiful cfystalUne 
substance called ' amygdalin.' Keither Hhe emulsin nor the amygdalin is 
p)oisonous, ueither have they any smell ; Init when both are mixed together in 
cold water the emulsin resolves the amygdalin into volatile or essential oil of 
bitter almonds, and into h3'drocyanic or prussic acid. Digested with cold 
water, bitter almonds gradually generate oil of bitter almonds and prussic acid ; 
digested with boiling water, or heated by themselves to the tem]ierature of 
212° Fahrenheit, the emulsin in almonds coagulates, and no oil of bitter 
almonds or prussic acid is formed." 
e hope to see, and we doubt not we shall see, the pulping 
system, with a due admixture of chaff, universally adopted for 
bullocks, horses, and sheep, as soon as the friction of the 
machines has been so far reduced as to render them as easy in 
