546 ME. J. B. LAWES AjSTD DE. J. H. GILBEET OX THE COIHPOSITIOX OE 
As already explained, in the cases to which these and the preceding Tables relating 
to Increase refer, the amounts and composition of the foods consumed to produce a given 
amount of increase, were determined by actual experiment ; and the composition of the 
increase so produced, is deduced from that of the animals that were analysed. Thus, in 
Table IX. for the Sheep, and in Table X. for the Pigs, are given the experimentalLy deter- 
mined amounts of dry substance, «&c., consumed to produce 100 lbs. of increase in hve- 
weight, and the estimated amounts of certain constituents in that 100 lbs. of increase. 
It is obvious, therefore, that we have an easy means of calculating the amount of the 
respective constituents stored up in increase, for 100 of dry matter consumed. The sum 
of these makes up the total dry matter in increase for 100 dry matter in food ; and the 
difference between this dry matter in increase and that in food represents the amount 
expired, perspiredj, or voided. With these observations, the mode of construction of 
Tables XIV. and XV. will be sufficiently intelligible. 
It was seen (in Table XII.), that in the Sheep there was probably an average of about 
9 parts dry substance fixed as increase for 100 consumed in food. Table XW'. shows 
(taking the cases in which the food was of the most usual description) that about S 
parts out of the 9 of dry increase were non-nitrogenous substance — that is fat. It re- 
sults then, that for 100 of dry substance in food, there would be little more than 1 part 
fixed in increase in other forms than fat -that is, as nitrogenous and mineral matters put 
together. According to the Table there were only, m Class I., 0-84, in Class III. 0-83. 
and in Class V. 0-74 part of nitrogenous substance retained in the increase of the animals 
for 100 of collective dry substance in their food. The corresponding amoimts of mineral 
matter fixed were, on the same basis of calculation, for Class I. ■0'25, for Class III. 0’24, 
and for Class V. 0-23. But if due allowance were made for the excess in the estimate 
of the mineral matters in the increase, as before noticed, the average amount of them 
stored up for 100 of dry food consumed, would, in the cases in question, be about 0’2. 
Taking the average of the cases in which the Sheep were fed upon food of a nature 
fairly representing that of the animals liberally fed for the butcher, it is assumed then, 
that for 100 parts of dry matter of such food, only about 9 parts Avere stored up as increase. 
There remained, therefore, 91 parts expired, perspired, or voided. In the food of Sheep 
(and of oxen also), the proportion of so-called “woody fibre” is very much greater than m 
that of Pigs. With the former, therefore, there Avill be a larger proportion of indigestible 
matter voided than with the latter ; and, as Avill presently be seen, with the larger pro- 
portion of digestible or assimilable matter in the food of the fattening Pig, there is at 
the same time a less proportion of the consumed dry substance exphed, persphed, or 
voided. 
At the head of the other results in Table XV. are given the amomits of the main 
classes of constituents stored up in increase for 100 of collecthe diy matter in food in 
the case of the analysed “fat Pig.” From the circumstances under Avhichthe data were 
obtained in this particular instance, it may be assumed that the figm’es exceedingly 
closely represent the actual facts. The indication is that, for 100 of dry matter of 
