THE FARMER'S MAGAZINE. 



be happy to show to any members of the Society who will do 

 me the houour of visitiug my little food museum at the Koyal 

 Agricultural College, Cirencester. Here is a specimen of a 

 nut cake. It is extremely sweet, and made of an African nut 

 that has lately come into commerce. The nut tastes as sweet 

 as an almond, and miy be eaten ; indeed, it is used as a dessert 

 nut occasionally. There are many other cakes of a similar 

 description, more or less important to the practical agricultu- 

 rist ; but I shall confine myself, with your permission, chiefly 

 to the chemistry of linseed cake, cotton cake, and rape cake. 

 Linseed cuke. — Vou are all well aware, we distinguish chiefly 

 the following kinds of linseed cake — English cake, American 

 cake, and Foreign cakes. Amongst foreign cakes there are 

 various descriptions. There is the Baltic, the Marseilles, the 

 Naples cake, and various others. We have here an excellent 

 specimen of good English cake, The English cake is made 

 now of two q\ialities — thick and thin cake ; the latter is made 

 in imitation of the American barrel cake, of which specimens 

 are before you. You obserfe how closely the thin English 

 cake resembles the American barrel-cake. The latter has 

 gained muci favour, and tlierefore the manufacturers in Eng- 

 land have found it to their advantage to imitate the form in 

 which it is sold. In the first place, notice, that the American 

 cake occasionally is as bad as English and foreign cakes. It is 

 not every description of American cake which is good ; but, 

 generally speaking, as it comes into the market, especially 

 the barrel cake, it is of a very superior character. But the 

 question, whether it is superior to the English cake or not, is 

 one which is not very readily decided. You may get English 

 cake quite as good, if not better than the American cake. 

 Some years ago it was the fashion to buy the English cake in 

 preference to any others ; but it is noT the fashion to buy the 

 American barrel cake. I can only account for this by the 

 fact, that the English cake, being produced in good quality, 

 was rapidly consumed ; the American cake was usually sent 

 in a very damaged condition to this country, coming as it did 

 in bags. Our sharp American friends very soon found that 

 they must send their cake here in a good condition. They 

 dried it previously to sending it over, aud imported it in bar- 

 rels; and this improved condition of the American cake greatly 

 increased its reputation, which has been kept up; so that at 

 the present time in most markets American cake, especially 

 the barrel cake, fetches a higher price than the English. But 

 a reference to the diagram will show you that there is no essen- 

 tial difference between good English cake and good American; 

 indred, if any thing, the advantage is in favour of the specimens 

 of English cake. The diflference is extremely small. There 

 is the same quantity of oil in both cases. The proportion of 

 flesh-forming matters is rather larger in the English ttian in 

 the American. There is the same amount of ash in both. The 

 proportion of sand hardly amounts to one per cent, in the 

 English cake, and in the American it is only a half per cent. 

 These diff'erences are extremely small andjuniroportant, so 

 that you may get, and often do get, as good English cake as 

 American. And occasionally also you get bad American cakes ; 

 but, on the whole, the exporters of American cake are very 

 jealoua as to the kind of article they send to this country, espe- 

 cially if they go to the expense of packing it in barrels. So 

 much with respect to the relative value of English and Ame- 

 rican cake. In the next place I have to notice some peculiari- 

 ties in the constitution of foreign cakes. I observe that most 

 of the foreign cakes which come from the south of France and 

 from the Bdltic are very inferior. It is difllcult indeed to get 

 a good foreign cake ; and a great deal of mischief is done by 

 these baj cakes. Animals do not get on well when fed upon 

 them, and frequently they suffer injury — injury which can 

 only be ascribed to deleterious seeds, with which almost inva- 

 riably the foreign cakes are mixed. We know but little of 

 the physiological effects which many of the weed seeds have 

 on the animal constitution ; but we know at least that several 

 of the weeds occurring in foreign cakes are violent purgatives. 

 Many English weeds also possess this property ; for instance, 

 the Ihium cathantictim. If you examine closely the foreign 

 cake, you will find in it, as in the case of the specimen I 

 hold in my hand, a considerable quantity of seeds that are 

 evidently not linseed. Moreover, it is another characteristic 

 property of foreign cakes, that they are often very hard pressed ; 

 they are frequently ground over, and pressed again a second 

 time in this country. Several of the foreign cakes are badly 

 pressed in the country where they are made, and are re-crushed 



iu this country, being mixed at the same time with the sweep- 

 ings of warehouses, with charlock, with rape seed, and refuse 

 seed containing a little oil, and the whole mess is then sold as 

 cake, to the great injury of those who feed it. I know for a 

 fact, that occasionally oily refuse seeds, which would have no 

 great value in an expressed state in the market, are pressed 

 with foreign cakes. Here is a sample of Marseilles cake, in 

 which you can see the foreign seeds very plainly. That the 

 foreign cakes are often re-crushed, appears to me to be proved 

 bj' the almost complete destruction of the shape of the linseed. 

 In this cake yon cannot possibly ascertain from what descrip- 

 tion of seed it is made. It is so finely ground that you can 

 hardly recognize the structure. This, of course, is not the 

 case with every foreign cake ; but many of the cakes are so 

 finely ground and hard pressed that it is impossible to say 

 what kind of cake the^' are, unless you examine tl:em very 

 carefully. While speaking of the different kinds of linseed 

 I would allude to the various adulterations of linseed cake. 

 The first and by far the most common one is adulteration with 

 the seeds of weeds, the sweepings of warehouses, refuse oil 

 seeds of various kinds. In the second place, an adulteration 

 by no means uncommon is that of bran. The bran is added 

 with a view of getting an additional quantity of oil out of the 

 cake by re-prcssing it. This spring 1 have had about half-a- 

 dozen, if not more cakes, sent to me, which were adulterated 

 with bran; and cakes mixed with seeds of weeds have been 

 sent to me, I am sorry to say, in a very much larger propor- 

 tion than pure unmixed linseed cake. Thirdly, linseed cake 

 is sometimes mixed with rapecake. A sample of such cake 

 was lately sent to me by Mr. Hudson, of Castleacre. Exam- 

 ined by the microscope, rapecake is unmistakably seen in this 

 cake. This adulteration perhaps is not so objectionable aa 

 many of the others which I have noticed ; but still as rapecake 

 sells at a much lower price than the American or English lin- 

 seed cake, I would advise all who like to buy the mixture to 

 buy the two cakes separately. Then again, chaff and the 

 seeds of cereals occur in cakes, especially in foreign cakes. 

 Even an unpractised eye will easily recognise in the sample of 

 Naples cake, which I bold iu my hand, the seeds of cereals, 

 refuse barley, and grass seeds. These are all mixed up with 

 the cake, and the wbo'e is pressed together. A very injurious 

 adulteration which occasionally occurs is that of castor-oil 

 beans. A member of this Society some time ago lost a valuable 

 animal by giving it Marseilles cake, in which I detected these 

 castor-oil beans. Another very injurious adulteration is that 

 which occurs — not very frequently, but 1 have seen it — an 

 adulteration of a cake, which is occasionally sold as manure, 

 under the name of nut-cake. It is produced by expressing the 

 seeds of Curcus beans— a very drastic seed which comes from 

 the Cape de Verde Islands. Only a few months ago a cargo 

 of these beans came into Bristol, and a bag of them got open 

 by accident. A number of street boys rushed after the beans, 

 and, finding them very sweet, partook of them. About a dozen 

 of them had to be carried half an hour afterwards to the Infir- 

 mary. They are violently drastic beans. They have an 

 agreeable sweet taste, but are very poisonous. These are some 

 of the more important adulterations that have come under my 

 notice. Leaving linseed cake, I proceed with the next de- 

 scription, namely, with Cotton Cake. We distinguish now 

 principally two kinds of cike ; the one made of the whole 

 seed, and the other of the shelled seed. The difference iu the 

 two qualities of cake will at once become intelligible by an 

 examination of the seeds, or the raw materials from which 

 the cakes are made. The decorticated or shelled cake is 

 made of the kernel of the cotton seed ; the whole cake, 

 in which we recognise an abundance of the husk, is made 

 of the entire seed ; and inasmuch as the cotton seed 

 contains full half its weight, and some descriptions contain 

 as much as 60 per cent, of the hard husk, we must not ex- 

 pect that the cake made of the whole seed should be as valu- 

 able as the decorticated cake. There are several specimens of 

 cottou cake on the table. There is very little value in the 

 husk itself; the difference in the two kinds of cotton cake, 

 then, arises from the different modes in which they are made. 

 The one, the decorticated cake, is made from the kernel ; the 

 other kind is made from the whole seed. The difference in 

 the composition of the two kinds of cake is very great. The 

 decorticated cotton rake contains 1 6 per cent, of oil (more than 

 any other description of cake), while the whole seed cake con- 

 tains only 6 per cent. The proportion of albuminous ov flesh- 



