Agricultural Chemistry . — Fig Feeding, 



463 



able progress of the animal. With this view the selection of the 

 foods in the First Series of experiments was considered less in 

 reference to their cost than to their composition, it being desired 

 to provide such as contrasted strongly with each other in this 

 respect. It was thought that greater definiteness of result would 

 thus be attained; and that the principle once elicited by this 

 means, the more economical substitutes for the foods employed, 

 could afterwards be easily pointed out. Thus : — 



As the highly nitrogenous food — a mixture of equal weights of 

 Beans and Lentils, was employed. 



As the comparatively Tzo/z-nitrogenous food — Indian corn meal. 



As providing a large amount of inert woody fibre — a consti- 

 tuent apparently so essential in the food of the ruminant — 

 Bran. 



Before entering upon the detail of the experiments it may be 

 remarked, that it was not the object of them to compare one 

 breed of pigs with another ; nor are they calculated to determine 

 the several practical points — such as the most profitable age for 

 rapid fatting, &c. ; so that, after giving a full account of the 

 circumstances of our own experiments, w^e must leave it to the 

 intelligent reader to decide how far the results obtained by us are 

 to be reached, or improved upon, under the perhaps different 

 circumstances of his own practice. 



In the selection of animals, it was only sought to get such as 

 resembled one another in character, age, and weight, in the several 

 pens ; and, with this view, a competent person was employed to 

 go to the various styes and markets in the neighbourhood to pur- 

 chase animals suited to our object. 



It would have been quite impossible to collect, and accurately 

 v/eigh and sample for analysis, the excrements throughout the 

 whole of so extensive a set of experiments as that we are about to 

 describe ; and it was determined, therefore, to devote a few ani- 

 mals separately to the subject of manure as Avell as increase. 

 These were placed upon rafters, which allowed the excrements to 

 pass through upon a sheet of zinc below, and to be collected for 

 analysis as described in our paper on " Sheep-feeding." In the 

 other cases the animals were kept well littered with straw, in 

 pens 7 feet by 8 feet, which were fitted up for the purpose in a 

 spacious barn. The food was, of course, in all cases accurately 

 weighed ; and the animals themselves were put into the scales 

 every fourteen days. 



ExPERi:\IENTS WITH PiGS SeRIES I. 



For this Series, which comprised 12 pens of 3 pigs each, 40 

 animals were purchased, as nearly as possible of the same cha- 



