Page:Popular Science Monthly Volume 45.djvu/447

Rh  the price of the butter. The butter-maker owes the aroma to the bacteria, for by their growth the materials in the cream are decomposed, and the compounds are formed which produce the flavors and odors of high-quality butter. Different species of bacteria vary much as to the flavors which they produce, some giving rise to good, some to extra fine, and others to a very poor quality of butter. A majority of our common dairy species produce good but not the highest quality of butter. Heretofore the butter-maker has had no means of securing the best flavoring bacteria; but now the bacteriologist can isolate and obtain in pure cultures those species which produce the best-flavored butter, and can furnish them to the creameries to use as starters in cream ripening. This artificial ripening of cream promises much for the near future, but it has so far been applied on only a small scale.



third summer session of the School of Applied Ethics is to be held at Plymouth, Mass., July 12th to August 15th. A special feature will be the attention given to the labor question and allied subjects in each of the departments. In the Department of Economics the relation of economics to social progress will be discussed by leading economists from different universities. In the Department of Ethics and History of Religion various phases of the labor problem in the past and present will be considered by a large corps of able educators. The relation of various forms of educational activity to ethical and social progress will be considered at a conference of educators and teachers, August 5th to 11th, and opportunity will be afforded for free and full discussion.

has been formed in Paris, with M. Pasteur at its head, to raise funds for the erection of a monument to the memory of M. Charcot.

a lecture at the Royal Institution on the Electric Discharge through Gases, Prof. J. J. Thomson deduced from experiments the conclusion that the conductivity of gases at a certain degree of rarefaction is greater than that of any metal, and almost infinitely greater molecule for molecule. At a higher degree of rarefaction, however, conductivity is diminished, and in a perfect vacuum, as has been shown by some of Prof. Dewar's experiments, it is probable that the discharge would not pass at all. From another series of experiments it was inferred that electric currents will cross a high vacuum freely though they produce no glow to indicate the fact.

man can not swim without having learned, while other animals can, is explained by Mr. Robinson in the Nineteenth Century. It is a question of atavism. When in great danger we make the defensive movements most familiar or instinctive to us. The first impulse of quadrupeds is to run away, and the movements of running sustain them in the water, while man, true to his simian ancestors, tries to catch hold of something, and pushes his arms up, with the sure result of himself going down.

colloidal form of gold, soluble in water containing basic acetate of cerium, is described by Herr Schottlander. The solution is of a very intense reddish-violet color, turning to carmine red in dilute solutions. The color still remains distinct in a solution containing only of gold. These solutions are obtained by precipitating a dilute solution of a salt of cerium mixed with gold, by means of a lye of potash or soda. The green precipitate obtained is then dissolved in warm dilute acetic acid. The acetate of soda then gives a violet-red precipitate containing all the gold in the liquor and a little basic acetate of cerium. On drying this precipitate an amorphous bronze-colored mass, soluble in water, is finally obtained.

French Museum of Natural History received, a few months ago, a specimen of that rarest of birds, the Apteryx. It was carefully kept in a warmed room and fed with expressly chosen and prepared meats, for it was not supposed it could thrive in a foreign climate and among strange associations. One day in October it was gone, and could not be found, though the whole Jardin des Plantes was searched for it, till early in March a dog smelled it out in one of the ventilating holes of a row of newly erected buildings, in the cellar of which it had endured cold and rain and snow through the winter, and lived on what it could pick up. Never had it been known to be in better condition.

culture, as we know it, according to an article quoted in Garden and Forrest from the Orchid Review, did not exist till early in the last century, when, in 1731, a dried specimen of the species Bletia verecunda was sent to Peter Collinson from the Bahamas. Collinson sent the tubers to the garden of a Mr. Wager, where they were nursed during the winter, and produced flowers in the next summer. Two of our North American cypripediums were cultivated, perhaps, as early as 1737. At the end of the century there were cultivated in English gardens, besides several hardy species, orchids which had been brought home by travelers and naval and military officers from