any means live on potatoes alone, as some travellers have said they do:  at Quito, the daily food of the inhabitants is lorco, a compound of potatoes and a large quantity of cheese.  Rice is often cited as one of the most nourishing articles of diet.  I am satisfied, however, after having lived in countries where rice is largely consumed, that it is anything but a substantial, or, for its bulk, nutritious article of sustenance.”—­("Rural Economy,” Amer. edition, p. 409.) These statements are further confirmed by the observations of M. Lequerri, who, during a long residence in India, paid particular attention to the manners and customs of the inhabitants of Pondicherry.  “Their food,” he states, “is almost entirely vegetable, and rice is the staple; the inferior castes only ever eat meat.  But all eat kari (curry), an article prepared with meat, fish, or vegetable, which is mixed with the rice, boiled in very little water.  It is requisite to have seen the Indians at their meals to have any idea of the enormous quantity of rice which they will put into their stomachs.  No European could cram so much at a time; and they very commonly allow that rice alone will not nourish them.  They very generally still eat a quantity of bread."[35] In regard to the proportion of nutritious matter contained in grains of various kinds, it may be remarked that the tables which have been constructed as the results of various experiments are liable to an objection, which will be more particularly adverted to under another head.  For example, two substances, by the process of ultimate analysis, may exhibit the same proportion of nitrogenous matter, and still differ very materially in their value as articles of food.  Much depends on the digestibility of the form in which this matter is presented to the digestive organs.  A strong illustration is afforded in the case of hay, the proportion of nutritive matter of which, about 9.71, would certainly not represent its power of affording nourishment to the human system.  It is in truth quite impossible to arrive at any other than approximate results from the operations of chemistry, as to the amount of nutriment contained in a given quantity or weight of any article of food.[36] It is perhaps not irrelevant to notice in this place some of the researches which have recently been made upon fermentation, and particularly its effects in the manufacture of bread.  It appears that when this process is brought about by the addition of yeast or leaven to the paste or dough, the character of the mass is materially altered.  A larger or smaller proportion of the flour is virtually lost.  According to Dr. William Gregory the loss amounts to the very large proportion of one-sixteenth part of the whole of the flour.  He says, “To avoid this loss, bread is now raised by means of carbonate of soda, or ammonia and a diluted acid, which are added to the dough, and the effect is perfectly satisfactory.  Equally good or better bread