1870.] Agriculture. 377 



Another artificial guano, containing 26 per cent, of water and 

 60 per cent, of lime and sand, &c, and not 1 per cent, of ammonia, 

 is sold at 70s., while it is not worth carrying a mile if it could be 

 had for nothing. Other manures still occasionally find purchasers, 

 though absolutely worthless, or even mischievous. Oil-cakes of 

 various kinds, as well as fertilizers, pass through Dr. Voelcker's 

 hands, and faulty samples, under analysis, lose the character under 

 which they have been bought and sold : and the publication by the 

 Koyal Agricultural Society of these investigations by their chemist 

 must ultimately prove serviceable. 



A very instructive discussion by Mr. Lawes on the waste of food 

 during respiration has been published with a view to the elucidation 

 of sound farm practice in the meat manufacture. It is obvious, as 

 he points out, that in the case of animals fed for the butcher the 

 economy of the feeding process will be the greater, the less the 

 amount of food expended by respiration in the production of a given 

 amount of increase ; and it is equally obvious that one ready and 

 efficient means of lessening the proportion of the waste or expen- 

 diture to the increase produced, is to lessen as far as possible the 

 time taken to produce it; in other words, to fatten as quickly as 

 possible. From numerous experiments made at Eothamsted it appears 

 that a pig weighing 100 lbs. will, if supplied with as much barley- 

 meal as he will eat, consume 500 lbs. of it, and double his weight — 

 that is, increase from 100 lbs. to 200 lbs. live weight — in seventeen 

 weeks. Of the 420 lbs. of dry substance which the 500 lbs. of 

 barley-meal contain, about seventy-four are stored up in the 100 lbs. 

 of increase in live weight, about seventy are recovered in the manure, 

 and 276, or nearly two-thirds of the whole, are given off into the 

 atmosphere by respiration and perspiration — that is to say, are ex- 

 pended in the mere sustenance of the living meat-making machine, 

 during the seventeen weeks required to produce the 100 lbs. of 

 increase. 



Mr. Lawes points out that if instead of allowing the pig to have 

 as much barley-meal as he will eat, the 500 lbs. of meal had been 

 made to last many more weeks, the result would have been that the 

 animal would have appropriated a correspondingly larger proportion 

 of the food for the purposes of respiration and perspiration, and a 

 correspondingly less proportion in the production of increase. In 

 other words, if the 500 lbs. of barley-meal were distributed over a 

 longer period of time, it would give less increase in live weight, and 

 a larger proportion of it would be employed in the mere maintenance 

 of the life of the animal. Indeed, if the period of consumption of the 

 500 lbs. of meal be sufficiently extended, the result will be that no 

 increase whatever will be produced, and that the whole of the food, 

 excepting the portion obtained as manure, will be expended in the 

 mere maintenance of the fife of the animal. 



