1'ILATION. 



VENTILATION. 



And in the same economical point of view, it 

 becomes an important question to ascertain, pro- 

 vided the result of modern experiments relating 

 to the formation of flesh and the generation of 

 beat is correct, and calculating from the data 

 which they furnish, the relative value of each 

 description of food. This has been attempted 

 Playfair, with a result which he thus 

 (Jour R. A. S. vol. vi. p. 560 : "All 

 food then has two distinct purposes, the forma- 

 tion of flesh, and the sustenance of animal heat. 

 The substances in vegetables destined for the 

 formation of flesh are perfectly identical with it 

 in composition, and are known by the names of 

 gluten, albumen, fibrin, or casein ; those which 

 re suited for the support of animal heat are not 

 at all similarly composed to flesh, and consist 

 of starch, gum, sugar, &c. Knowing these facts, 

 it becomes a money question as to the value of 

 particular kinds of food for the support of the 

 frame. We know how much of flesh-giving 

 principle each variety of food contains, and 

 therefore we can at once estimate how much of 

 each it will be necessary to consume to obtain 

 one pound of real nutriment, and what the cost 

 of that pound will be to the consumer. The 

 olio wing table is constructed on this principle, 

 bat as prices vary in different localities, these may 

 be altered to suit the peculiar case : in the table, 



jrarc given at tberate at which the respective 

 substances might be purchased in London under 

 fcrourable circumstances. 



Quantity of Food necessary to produce 1 fb. of 

 J<*kiQ*4 tke Money-Cost of it* production. 

 25 Ibs. of milk furnish 1 Ib. of flesh, . s. d. 



' perceive the potato takes its proper rank. 1 Ib. of 

 carbonaceous fuel to sustain animal heat would 

 be furnished by different weights of the r ol lowing 

 articles at the English prices named : 4 Ibs. of 

 potatoes, 2|</. ; 10 Ibs. carrots, 2d. ; 1| Ib. flour, 

 28-10rf.; 1| Ib. barleymeal, 2d. ; 11 1-10 Ib. 



| turnips, 2d. ; 1| Ib. oatmeal, 3frf. ; 1 9-10 Ib. 

 beans, 3f/. ; 1 9-10 Ib. peas, 3 8-10rf.; 2 Ib. 



i bread, 4</. ; 11 9-10 Ib. milk, Is. 5d. These esti- 

 mates must, however, be considered as rough 

 approximations. 



't will not be unattended with benefit if we 

 contrast these valuable scientific researches upon 

 the cost of production with the results of the 

 trials of a practical Scotch farmer. 



From some careful experiments of Mr. Bruce, 

 of Waughton, in East Lothian (Trans. High. 

 Soc. 1846, p 375), with linseed cake and other 

 substances in sheep feeding, he concludes that 

 " mutton can be produced at a lower rate per Ib. 

 upon liberal use of foreign keep along with tur- 

 nips, than upon turnips alone, taking of course 

 the increased value of the manure into account;" 

 that of this foreign keep " linseed is the most valu- 

 able, and beans the least so; but that the mixture 

 of both forms a useful and nutritious article of 

 food. In his trials 95 Cheviot ewes were di- 

 vided into five lots, and enclosed, and fed with 

 turnip tops and the following subsiances, upon 

 portions of equally sheltered grass land. Lot 

 A consisted of 15 ewes, B, C, D, and E, of 20 

 each. 



and cost 03 



turnips 02 



potatoes 02 



carrots 02 



butcher's meat, free from 

 fat and bone, furnish 1 

 Ib. of flesh, and cost, 2 



oatmeal 01 



barleymeal 01 



bread . . . ..01 



flour .01 



... 



... o o ., 



~et us look *t thA various kinds of food with 

 reference to t^eir value as fuel, and we shall 

 1068 



100 " 



50 " 



50 



A tt 



g 



7 ?v 



3| " 



3 iO 



i::; 



See ORGANIC CHEMISTRY, FOOD, GELATIN, VE- 

 GETABLE CHEMISTRY, and other heads relating to 

 these subjects. 



VERBENA. See VERVAIN. 



VERJUICE. An acid liquor, prepared from 

 the twigs of the vine, or from grapes or apples 

 that are unfit to bp converted into wine or cider. 

 It is also made from the wild crab apples. 



