If one must prepare his own rennet, the better way is to do it in a lump before the cheese-making season begins. Get a strong barrel and a pounder--such as used by washerwomen; also a wringer. Take old rennets and cut them into strips. Make a weak brine of pure water, by using one pound of salt to twenty pounds of water, and in this, soak, pound and wring your rennets. Hang them up and freeze them; then soak, pound and wring them again; and so on as long as you can get any strength. When done, carefully settle, skim, and strain your liquid. Put it in a clean barrel or stone jars, put in all the salt that it will dissolve, so that a little will settle on the bottom, then stop or cover tight; put in a cool place and take from it as wanted for use. There is nothing better than saturated brine for keeping animal products. Be sure, however, that you use only the purest dairy salt in preparing brine. Some say that only stone jars should be used for keeping rennet. We have used an ash tub for the amount prepared weekly. To keep the wood from tainting, we invariably, every time we dipped out rennet and exposed new surface, rubbed it with salt. EXCLUDING AIR. Rennet could be much more easily kept sweet if put in an air-tight vessel. The "American Dispensatory" says: "When gastric juice is completely protected from the air it may be kept unchanged for a longtime; but on exposure it speedily undergoes decomposition, acquires a very offensive odor, and loses its characteristic digestive property." We think that the Dispensatory is right. The composition of pure gastric juice is as follows: Water, 97.00; salts, 1.75; pepsin, 1.25; total, 100.00. There is also a small amount of free acid. Both rennet extract and pepsin are used as medicine. CURING ROOMS. It is hard to determine which is of the greater importance, good rennet or properly constructed curing-rooms; for both are necessary to the production of the best cheese, while the want of either is sure to injure if not to spoil it. The importance of controlling the temperature in curing has not yet taken hold of the popular mind. The best milk in the world may be spoiled by bad rennet, and the best curd in the world may be spoiled by a bad curing-room. TEMPERATURE.