Page:Popular Science Monthly Volume 39.djvu/293

Rh idea that you were eating nectarines, figs, etc., and sometimes a delicious compound with a dash of mushroom flavor in it. The flavors of choice mangoes are infinite, and their size varies from that of a small hen's egg to that of a good-sized melon or ostrichegg. A choice mango can be scooped out with a spoon, and it has the texture of a stiff curd."

Cultivation of Alpine Plants.—An Alpine botanical garden for the cultivation of mountain plants has been established in Valais, under the auspices of the Association for the Protection of Plants, and was opened on the 21st of July, 1889. It includes about a hectare of land, and is situated at the height of 1,633 metres above the sea, above the village of Bourg-SaintPierre in the Val d'Entremont, on the Great St. Bernard road, and some three or four hours from the Hospice. The tract consists of a hill about sixty metres high, and presents the variety of soil and slope, of wet, dry, and stony tracts that promise to be best adapted to the wants of the various species that will be planted upon it. It is called the Linnæa, and has been placed under the special care of an international committee, whose headquarters will be at Geneva. M. Arthur de Claperède, of Geneva, has been chosen president of this committee; and Dr. Bailey, of Bourg-Saint-Pierre, vicepresident. Among its twenty-five members are Sir John Lubbock and Mr. G. J. Romanes. Visitors not members of the protecting societies of the institution will be charged fifty centimes for admission to the grounds, and perpetual tickets will be issued to those making gifts of ten francs or more.

Climatic Conditions of the Glacial Period.—According to Prof. Warren Upham's paper on the climatic conditions of the Glacial period, the formation of the great ice-sheet should be promoted by long-continued rather than an excessive cold, and an abundant supply of moisture by storms, giving plentiful precipitation of snow during more of the year than now, so as to include in the time of snow accumulation not only the present winter but also the autumn and spring months. The summers, too, were probably cooler in glacial times than now, for their heat was not sufficient to melt away the accumulated snow, which gradually increased in thickness from year to year, its lower part being changed to ice. When large portions of continents became thus ice-coated, the storms sweeping over them would be so rapidly cooled that the greater part of their snow-fall would take place upon the borders of the ice-sheet, within probably from fifty to two hundred miles from its margin; but the snow-fall during the advance of the ice was probably in excess of the amount of evaporation and melting over the whole ice-covered area. In New England and New York the average ascent of the ice was from twenty-five to thirty feet per mile for the first one hundred to two hundred miles from its boundary. Toward its center the slope diminished, as on the interior ice of Greenland; but the ice-sheet enveloping the northeastern part of North America probably attained, as estimated by Prof. Dana, a maximum thickness of about two miles on the Laurentian highlands between the river St. Lawrence and Hudson Bay.

Cocoa.—Cocoa in its natural state contains a large proportion of fat, so that it can not be taken by persons suffering from weak digestion. The presence of so much fat prevents the easy solution of the naturally soluble portions, which are more or less locked up in the fat. This difficulty was encountered and overcome by the Indians and Mexicans in the same way as our cocoa manufacturers first overcame it—by adding to the powdered cocoa sugar and starch as diluents. Or a considerable part of the fat can be removed by pressure. Chemical analysis has shown that the estimation in which cocoa was held by the inhabitants of the countries in which it was first produced rested on scientific as well as on practical grounds. Our manufacturers are working now on the same lines as did the natives of Central America three hundred years ago, and the additions they make to cocoa are only imitations of what was done in ancient times to make its use more acceptable. As compared with tea and coffee, cocoa is deficient in those aromatic properties which have an exciting effect on the nerves of taste and smell. It has about as much of alkaloids as coffee, but