So far from this, there ought to be less loss of ingredients than we have supposed in our illustrative figures. But more of the butter is cut and runs off with the whey when the acid is developed before drawing the whey. The aim of the "sweet curd" system is to avoid this waste as much as possible, especially that of the butter and ash. To effect this, the whey is drawn sweet and the acid allowed to develop after the curd is cooked and the whey expelled. There need be no more water left in the curd, but more butter and ash, both of which tend to make the cheese softer. But with proper curing rooms, there is no trouble in making the cheese firm enough for all practical purposes, including shipping. It is better to use less rennet and not have coagulation begin under 25 minutes, cutting the curd about 15 or 20 minutes later, and to take more time for curing, at a lower temperature. We then have a firmer, more buttery, and better flavored cheese, which is a desideratum. But, with high and changing temperature in the curing room, no certain or satisfactory results can be counted on. THEORY AND PRACTICE. In theory, we ought to prevent the waste of butter and caseous matter altogether; but in practice, there is always a little loss of butter, and there are certain albuminous ingredients, called by the Germans _ziega_, which rennet will not coagulate. There is, of course, no means of saving this. The sugar we cannot and do not want to save in the cheese. If retained, it would be injurious and probably spoil the cheese, as the lactic acid in the small amount of sugar retained in the water is all that we can well manage. But all matter coagulable by rennet, all the butter, and all the ash, we ought to retain; and we cannot really call ourselves scientific cheese makers until we can do this. When accomplished, a greater weight of cheese will be the result. There is no avoiding the acid resulting from the small amount of sugar retained in the curd; but, having expelled sufficient whey, if we keep the curd warm enough, and hold it in the vat or the sink long enough, the lactic acid will come on and we shall get rid of the bad results of putting a curd to press sweet. This acidity is absolutely necessary with the generality of curing rooms. But with low and steady temperature in the curing room, we can do about as we please. RENNET. Our recent observations more than ever convince us of the importance of good rennet in cheese making. Great evils and losses result from the use of bad rennet; and the great trouble is that many cheese makers do not know when rennet is bad. There is not only the evil of diseased and tainted rennets, to begin with, but the preparation from good rennets is often spoiled in the preparing. Frequently, in hot weather, they are allowed to taint while soaking; and when the liquid is prepared sweet, it is often allowed to ferment and taint for want of sufficient salt and from exposure in a high temperature.