Page:Popular Science Monthly Volume 41.djvu/585

Rh to be removed from the plant, then placed in wet sand and pulled open, so as to allow the sun and the air to ripen the pollen, which is carefully removed and placed on the finest single blooms. Calceolarias are shy seeders, and the most careful hybridization is necessary to insure a crop. Every bloom is examined, and the pollen is taken from the stamens and placed on the pistil. As the operation must be performed when the pollen is quite ripe, the flowers must be looked through nearly every day to catch each bloom as it comes to maturity. Seed is very difficult to obtain from carnations, and then only in small quantities. The commoner kinds of annuals are grown in masses. The plan of improving stocks of seed is as follows: As soon as the plants are fully in bloom they are carefully examined, and the best and truest in color or shape are marked by placing a stick next to them. When the seed is ripe they are carefully gathered by themselves, and kept for stock the following year. This is very necessary in case of some annuals, which show a great tendency to revert to the wild state; at the same time it improves the stocks from year to year.

Aluminium in Food-vessels.—Opinions still differ with regard to the value of aluminum for use in food-containing vessels. Messrs. Lübbert and Roscher asserted several months ago, in a paper on the subject, that aluminum was too readily acted upon by food-substances or other substances used in cooking, for its application in the construction of kitchen utensils to be safe. Prof. Lunge afterward instituted experiments on the subject, from which he concluded that coffee, tea, and beer had practically no action on aluminum, and the action of brandy was very slight; while that of acids and acid liquids (wine, sour milk, and fruit juices) was more pronounced, but still too slight to cause alarm. Taking the worst case, that of acetic acid, this author found a maximum attack of five milligrammes per one hundred square centimetres in six days; so that a given vessel, kept always full, would be reduced to half its original weight in fifty-five years. This, he holds, is too trifling an action to be considered. There is no danger of any injurious action upon the human body by aluminum compounds, which, moreover, are not poisonous as compounds of arsenic, mercury, lead, and copper are poisonous. Before they can act injuriously, a quantity will have to be ingested a hundred times larger than he found to be regularly entering the stomach in this way. Finally, he adds, aluminum may be employed without fear for canteens or any other vessels used to hold food, at least at ordinary temperatures. Against these conclusions is a report on the authority of the telegraph of a soldier near Nuremberg, Germany, who was taken sick after drinking cognac from his aluminum flask. On analysis of the brandy it was found to be muddy, and to contain roundish, black particles, which proved to be aluminum and iron. But in this case we had not simple corrosion of aluminum by brandy, but galvanic action of the liquor, aluminum, and iron, with resultant corrosion. Further investigation of the subject is needed.

Photography in Colors.—M. G. Lippaman announces that he has perfected a method of photographing in colors which he mentioned to the French Academy of Sciences fourteen months ago, and has exhibited very brilliant spectra which he obtained without the interposition of the colored screen. The author claims to have obtained the compound colors of natural objects as well as the natural colors of the spectrum. He exhibits a series of plates representing a window of four colors—yellow, green, blue, and red; a trophy of French and other flags; a plate of oranges with a red poppy on top; and a many-colored parrot. The window and the parrot are of dazzling brilliancy. They were photographed with the electric light in ten minutes. M. Lippaman admits that the plates require in practice too long an exposure, and that it will be necessary to make them more sensitive.

Influence of Natural Surroundings on Human Character.—Captain F. E. Younghusband makes a remark in one of his accounts of central Asiatic exploration, on the influence of the natural surroundings on the character of the people of a country. "It has been my fortune," he says, "to travel in very varied descriptions of country—in the dense, gloomy forests of Manchuria; over the bounding grassy steppes of Mongolia; across the desolate wastes of the Desert of Gobi;