Whether skimming off the cream or drawing off the milk be practiced, the question arises as to the proper time for performing the operation. The more general practice is to "skim" just as the milk gives unmistakable signs of acidity, or thickens a very little on the bottom of the pan or can. A few prefer to skim the cream sweet, and still another few let the milk lopper. This wide divergence of opinion and practice shows how very imperfectly is the real philosophy of butter making understood; but, notwithstanding this, each one is usually very tenacious in his belief as to the superiority of his own practice. A few fancy butter makers say that the finest butter is made from sweet cream, raised in cold air by shallow setting. It is insisted by them that airing and oxydizing, and not souring, is what "ripens" cream and fits it for easy churning, while this airing and oxydizing imparts the fine aroma so much desired in the finest butter. This view of the origin or development of flavor is sustained by experiments made at Cornell University, at the suggestion or under the supervision of Prof. L.B. Arnold. It is also claimed that the lack of flavor and the short-keeping of sweet-cream butter churned from cream raised by deep setting is due to its lack of oxygen, and that souring the cream thus raised, before churning, both oxydizes it and imparts a ranker and more positive flavor resulting from the effects of the lactic acid. We think both propositions look reasonable, and we should like to see a series of scientific experiments made to determine both the effects of oxygen and the effects of lactic acid on the butter product of cream. At present, theory and practice vary so widely with different butter makers who turn out a high-priced butter for the market, that one is led to doubt all theories and query whether the quality of butter does not depend on something not yet known, which is independent of all current theories and practices. CHURNING. And as to the proper time of churning, there is an equal divergence of opinion and practice. One churns his cream sweet, another wants it slightly changed, a third wants positive acidity in the cream, and a fourth loppers the cream, while a fifth lets the cream stand even twelve hours after loppering--and this extremely sour cream butter sells for the very highest market price. So we are left all at sea, so far as acidity is an element in butter making. Again, to further illustrate these extremes, while a gentleman in Vermont is setting his neighbors agog by raising cream in a vacuum, a Canada gentleman is experimenting with an invention to raise cream by hydrostatic pressure and get the fat of the milk so pure as to dispense with churning. We hope both will succeed. TEMPERATURES.