In boiling eggs, the effect of heat in hardening the albumen is well known; by being suddenly plunged into boiling water, the outside is hardened to the greatest degree of which it is capable, and is thereby rendered extremely difficult of digestion, whilst the inside is barely warmed; if, on the contrary, they are placed in cold water, which is then raised to the boiling point, removed from the fire, and allowed to stand about a minute (or two, if required to be well done), it will be found that, instead of having an almost leathery consistence, the white will be uniformly partially hardened, and will furnish a much more pleasant and digestible article of diet; the improvement, in fact, is so great, the common eggs cooked in this manner very nearly approach new-laid ones in quality. If the operation of boiling has to be performed on any substance containing starchy matters—as potatoes, rice, flour, &c., then the heat must, on the contrary, be raised to a sufficient degree to burst the little grains of which the starch consists, and liberate the interior nutritious portions, before it can become fit food for man; uncooked starch not being readily or easily digested. And even in the case of those vegetable-feeding animals whose power of digesting such substances surpasses that of man, there is the greatest advantage to be derived from the use of cooked food, as the most intelligent and scientific farmers at the present day well know; and we would strongly urge on those of our readers who keep pigs, to try the experiment of baking the potatoes they give them, for this process, like boiling, has the effect of bursting the starch grains; they will find the effect to be that the food will go much further, all of it being digested, and that the quality of the flesh will be very materially improved. IX. ECONOMY OF HEAT.