Some may say that the preceding observations are merely theoretical; and may demand the support of actual trial, before they will concede that the selection of the most nourishing and wholesome diet is hereafter to be regulated by the results of chemical analysis. The demand is reasonable in itself, and the so-called deductions of theory are entitled only to the rank of probable conjectures, till they have been tested by exact and repeated trials. But such in this case have been made; and our theoretical considerations come in only to confirm the results of previous experiments--to explain why these results should have been obtained, and to extend and enforce the practical lessons which the results themselves appeared to inculcate. Thus, from the experiments of Majendie and others, it was known that animals which in a few weeks died if fed only upon fine flour, lived long upon whole meal bread. The reason appears from our analytical investigations. The whole meal contains in large quantity the three forms of matter by which the several parts of the body are sustained, or successively renewed. We may feed a man long upon bread and water only, but unless we wish to kill him also, we must have the apparent cruelty to restrict him to the coarser kinds of bread. The charity which should supply him with fine white loaves instead, would in effect kill him by a lingering starvation. Again, the pork-grower who buys bran from the miller, wonders at the remarkable feeding and fattening effect which this apparently woody and useless material has upon his animals. The surprise ceases, however, and the practice is encouraged, and extended to other creatures, when the researches of the laboratory explain to him what the food itself contains, and what his growing animal requires. Economy as well as comfort follow from an exact acquaintance with the wants of our bodies in their several conditions, and with the composition of the various articles of diet which are at our command. In the present condition of the country, this economy has become a vital question. It is a kind of Christian duty in every one to practise it as far as his means and his knowledge enable him. Perhaps the amount of the economy which would follow the use of whole meal instead of fine flour, may not strike every one who reads the above observations. The saving arises from two sources. First, The amount of husk, separated by the miller from the wheat which he grinds, and which is not sold for human use, varies very much. I think we do not over-estimate it, when we consider it as forming one-eighth of the whole. On this supposition, eight pounds of wheat yield seven of flour consumed by man, and one of pollard and bran which are given to animals--chiefly to poultry and pigs. If the whole meal be used, however, eight pounds of flour will be obtained, or eight people will be fed by the same weight of grain which only fed seven before.