supplement. SCIENCE AND ART OF AGRICULTURE. 1.301 



exposed to a cold atmosphere in the open fields. It is well known that the more bodily labour to which 

 a man is subjected the more food must he receive to supply the tissues wasted in that labour In the 

 late distress in Lancashire the poor sufferers who often were unable to obtain sustenance for them-el el 

 and lamihes, discovered, through the force of necessity, both the theories which we have endeavoured 

 to expound, viz. that warmth is an equivalent for food, and that motion is always accompanied b»a 

 change of matter. \\ e are informed by the daily press that whole families remained in bed for days to- 

 gether covered with as many clothes as their small stock could furnish. In this state the animal heat 

 was artificially retained, and little matter being expended in motion, a small amount of food was s.iffi 

 cient to support the vital principle." (Journ. R. A. S £., vol. iv. p. 227.) 

 ° ^■Theimportance of knowing how much water each kind of food contains, has been forcibly pointed 

 by Dr. Playtair, who has furnished the tollowing table : ' H 



8119. 

 out 



100 lbs. of Peas 

 Beans 



Lentils 



Oats 



Oatmeal - 



Barley meal 



Hay 



Wheat straw 



Turnips ' - 



Swedish turnips 



Mangold-wurzel 



White carrot 



Potatoes - 



Red-beet - 



Linseed-cake 



Bran 



Thus, in giving a pig 100 lbs. of potatoes, we actually give it only 28 lbs., because 72 per cent, of this food 

 consists of water. 



8120. The comparative values of different kinds of food, as far as the production of flesh or muscular 

 fibre is concerned, is not less important ; because, as we have before seen, those kinds of food which do 

 not contain nitrogen are only productive of fat or heat. The following table is given by Dr. I'layiair : 



100 lbs. of Flesh 

 _ Blood 



- contain 



Beans 

 Peas 

 Lentils 

 Potatoes - 

 Oats 



Barley meal 

 Hay 



Turnips - 

 Carrot 

 Red-beet - 



Albumen. 



lbs. 



25 



20 



31 



29 



33 



2 

 11 

 14 



8 



1 



2 



u 



Unazotised Matter. 



lbs. 









 514 



511 



48 

 25 

 68 

 68* 



68£ 



9 

 10 



84 



In a cold day animals ought to be furnished with food containing a considerable amount of unazotised 

 ingredients, in order to protect them from the effects of the cold. Potatoes are of great use in keeping 

 up the heat of the body, and in forming tallow ; but are in the highest degree unprofitable for forming 

 flesh. " It will be seen by the table, that 1550 lbs. of potatoes would be required to form the same quan- 

 tity of flesh that 100 lbs. of beans would do ; whilst little more than 200 lbs. would suffice to form the 

 same quantity of tallow ; hence the great advantage of mixing food, so as to supply in smaller bulk those 

 constituents, of which one kind of food is deficient. Sheep fed on oil-cake increase in weight faster than 

 on any other kind of food, but they feel quite soft, and when fat handle like a bag of oil. This is because 

 they receive food which contains very little albumen to form flesh, so that tallow is the only product. But 

 if with the oil-cake they receive oats or barley, they are firm to the touch, and possess plenty of good 

 flesh, and the fat lies equally distributed amongst the muscular fibre. The reason here also is obvious ; 

 for both oats and barley contain much albumen (or, chemically, gluten). In an experiment made by 

 Mr. Morton at LordDucie's farm, twenty-eight pigs, put up in pens of seven each, and fed on an average 

 on 15$ lbs. of potatoes and 4 lbs. of barley-meal each, gained 15 or 16 lbs. weekly. In this quantity, the 

 pigs actually consumed nearly equal quantities of the two kinds of food, or exactly 30 lbs of dry potatoes, 

 and 23 lbs. of dry barley-meal weekly. The increase in weight being 16 lbs. for "each pig, 87 lbs. of the 

 food were lost in supporting respiration, and the necessary muscular movements, even without taking 

 into calculation the water contained in the flesh of the animal, which amounts to 75 per cent. If these 

 animals had been deprived of muscular movement, by being placed in narrow warm cribs, it is reasonable 

 to suppose that less food would have been lost, because less would have been consumed in the production 

 of force, and in sustaining the animal heat. The barley-meal contains the constituents for furnishing 

 firm flesh, as well as for producing tallow, or supporting respiration. The economy of using potatoes, 

 consisted in their supporting the respiration of the animals at less expense than barley. The 108 lbs. of 

 potatoes used in the week for this purpose, and for the production of tallow, contain 26 lbs. of unazotised 

 matter. In order to replace this, 33 lbs. of barley-meal would be requisite. It does not invalidate the 

 conclusion, that 33 lbs. of barley-meal would produce a greater return than 108 lbs. of potatoes, because 

 the former contains much more albumen and less water than the latter." {Journ. B. A. S. E., vol. iv. 

 p. 233.) 



8121. The equivalent values of different kinds of food, if they could be correctly ascertained, would be 

 of great value to the farmer, and the following table, translated from the French by Mr. Rham, may be 

 considered as near an approximation as can be obtained in the present state of our knowledge. On "this 

 table Dr. Playfair observes that an animal in a hot day will require much less food than in a cold day ; 

 that equivalence of food may be correct as far as the same animal is concerned, but may be of little value 

 as regards other animals, because the size of the lungs of an animal occasions a great difference in the 

 amount of food consumed. 



4 3 



