We have determined the average length of life of the adepts of the science of the sky who died before 1780 and of those who have died since that year. We have obtained sixty-three years and six months for the former, and sixty-four years and eleven months for the latter. The advantage in favor of these is not to be despised.
Taking a hundred individuals in each of these categories, there died at different ages:
| Before 1870. | After 1870. | |
| Before seventy years of age | 62 | 57 |
| Between seventy and seventy-nine | 23 | 28 |
| Between eighty and eighty-nine | 12 | 13 |
| Between ninety and ninety-nine | 2 | 2 |
| Over a hundred | 1 | 0 |
The conclusion at which we arrive has already probably occurred to more than one reader. Become an astronomer, if you wish to live long. We will add, whoever follows this counsel will not only see the limits of his life far removed, but he will also find in the study and contemplation of the heavenly bodies a satisfaction more durable than any earthly pleasures.—Translated for the Popular Science Monthly from Ciel et Terre.
| THE CHEMISTRY OF COOKERY. |
By W. MATTIEU WILLIAMS.
XXVIII.
I NOW proceed to examine the chemical changes which occur in the course of the cookery of vegetable substances used for food. My readers will remember that I referred to Haller's statement, "Dimidium corporis humani gluten est," which applies to animals generally, viz., that half of their substance is gelatine, or that which by cookery becomes gelatine. This abundance depends upon the fact that the walls of the cells and the framework of the tissues are composed of this material.
In the vegetable structure we encounter a close analogy to this. Cellular structure is still more clearly defined than in the animal, as may be easily seen with the help of a very moderate microscopic power. Pluck one of the fibrils that you see shooting down into the water of the hyacinth-glasses just at this season, or, failing one of these, any other succulent rootlet. Crush it between two pieces of glass, and examine. At the end there is a loose, spongy mass of round cells; these merge into oblong rectangular cells surrounding a central axis of spiral tube or tubes, or greatly elongated cell-structure. Take a thin slice of stem, or leaf, or flower, or bark, or pith, examine in like manner, and cellular structure of some kind will display itself, clearly demon-
