to be that the cream has become infested with an abundance of malign species. The ripening that they produce is therefore an undesirable one, and the quality of the butter is sure to suffer. So long as butter was made only in private dairies it was a matter of comparatively little importance if there was an occasional falling off in quality of this sort. When it was made a few pounds at a time, and only once or twice a week, it was not a very serious matter if a few churnings of butter did suffer in quality. But to-day the butter-making industries are becoming more and more concentrated into large creameries, and it is a matter of a good deal more importance to discover some means by which a uniformly high quality can be insured. If a creamery which makes five hundred pounds of butter per day suffers from such an injurious ripening, the quality of its butter will fall off to such an extent as to command a lower price, and the creamery suffers materially. Perhaps the continuation of such a trouble for two or three weeks would make a difference between financial success and failure in the creamery. With our concentration of the butter- making industries it is becoming thus desirable to discover some means of regulating this process more accurately. The remedy of these occasional ill effects in cream ripening has not been within the reach of the butter maker. The butter maker must make butter with the cream that is furnished him, and if that cream is already impregnated with malign species of bacteria he is helpless. It is true that much can be done to remedy these difficulties by the exercise of especial care in the barns of the patrons of the creamery. If the barns, the cows, the dairies, the milk vessels, etc., are all kept in condition of strict cleanliness, if especial care is taken particularly at the seasons of the year when trouble is likely to arise, and if some attention is paid to the kind of food which the cattle eat, as a rule the cream will not become infected with injurious bacteria. It may be taken as a demonstrated fact that these malign bacteria come from sources of filth, and the careful avoidance of all such sources of filth will in a very large measure prevent their occurrence in the cream. Such measures as these have been found to be practicable in many creameries. Creameries which make the highest priced and the most uniform quality of butter are those in which the greatest care is taken in the barns and dairies to insure cleanliness and in the handling of the milk and cream. With such attention a large portion of the trouble which arises in the creameries from malign bacteria may be avoided.