promontories, indicates that many former islands are now connected with the mainland. The islands of Imeleb and Quehui, in Chiloe, are at present separated only at high water, and appear to be approaching a permanent union.—Translated for the Popular Science Monthly from Die Natur.
|THE CHEMISTRY OF COOKERY.|
IN my last I referred to Rumford's anticipation of the results of modern chemical analysis in his selection of the materials for his economical feeding of the poor of Munich; but, as may be supposed, all his theoretical speculations have not been confirmed. The composition of water had just been discovered, and he found by experience that a given quantity of solid food was more satisfying to the appetite and more effective in nutrition when made into soup by long boiling with water. This led him to suppose that the water itself was decomposed by cookery, and its elements recombined or united with other elements, and thus became nutritious by being converted into the tissues of plants and animals.
Thus, speaking of the barley which formed an important constituent of his soup, he says: "It requires, it is true, a great deal of boiling; but, when it is properly managed, it thickens a vast quantity of water, and, as I suppose, prepares it for decomposition" (the italics are his own).
We now know that this idea of decomposing water by such means is a mistake; but, in my own opinion, there is something behind it which still remains to be learned by modern chemists. In my endeavors to fathom the rationale of the changes which occur in cookery, I have been (as my readers will remember) continually driven into hypotheses of hydration, i. e., of supposing that some of the water used in cookery unites to form true chemical compounds with certain of the constituents of the food. As already stated, when I commenced this subject I had no idea of its suggestiveness, of the wide field of research which it has opened out. One of these lines of research is the demonstration of such true chemical hydration of cooked gelatine, fibrine, cellulose, casein, starch, legumin, etc. That water is with them when they are cooked is evident enough, but that water is brought into actual chemical combination with them in such wise as to form new compounds of additional nutritive value proportionate to the chemical addition of water demands so much investigation that I have been driven to merely theorize where I ought to demonstrate.
The fact that the living body which our food is building up and