Page:Popular Science Monthly Volume 23.djvu/387

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THE CHEMISTRY OF COOKERY.

a turn. There are other points of a practical nature with regard to this invention which I can not now describe.

There is one other class of instruments which I have developed, of which time will let me say very little. The object of this class of instruments is to divide the speed with which two registrations are being effected, and continuously record the quotient. In the instrument on the table two iron cones are caused to rotate in time with the registrations; a magnetized steel reel hangs on below. This reel turns about, and runs up or down the cones until it finds a place at which it can roll at ease. Its position at once indicates the ratio of the speeds which will be efficiency, horse-power per hour, or one thing in terms of another. Just as the integrators are derived from the steering of an ordinary bicycle, so this instrument is derived from the double steering of the "Otto" bicycle.

Though I am afraid that I have not succeeded in the short time at my disposal in making clear all the points on which I have touched, yet I hope that I have done something to remove the very prevalent opinion that meters for power and electricity do not exist.

 

THE CHEMISTRY OF COOKERY.
By W. MATTIEU WILLIAMS.

IV.—ALBUMEN AND ITS CHANGES.

LET us now make practical application of the laws of albumen coagulation that were demonstrated in the test-tube experiment. The non-professional student may do this at the breakfast fireside. The apparatus required is a saucepan large enough for boiling a pint of water—the materials two eggs.

Cook the first in the orthodox manner by keeping it in boiling water three and a half minutes. Then place the second in this same boiling water; but, instead of keeping the saucepan over the fire, place it on the hearth and leave it there, with the egg in it, about ten minutes or more. A still better way of making the comparative experiment is to use for the second egg a water-bath, or bain marie of the French scientific cook; a vessel immersed in boiling or nearly boiling water, like a glue-pot, and therefore not quite so hot as its source of heat. In this case a thermometer should be used, and the water surrounding the egg be kept at or near 180° Fahr. Time of immersion about ten minutes or more.

A comparison of results will show that the egg that has been cooked at a temperature of more than 30° below the boiling-point of water is tender and delicate, evenly so throughout, no part being hard while another part is semi-raw and slimy.