THE CHEMISTRY OF COOKERY. 373 



a turn. Thei'e 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 in- 

 struments 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 registra- 

 tions ; 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 an- 

 other. Just as the integrators are derived from the steering of an 

 ordinary bicycle, so this instrument is derived from the double steer- 

 ing 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 CHEMISTEY OF COOKEKT. 



Br 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 min- 

 utes or more. A still better way of making the comparative experi- 

 ment 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 sur- 

 rounding 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. 



