268 EXPERIMENT STATION RECORD. [Vol.35 



Other figures show the effect of oven temperature on the time of cooking of 

 beef roasts and on losses in weight and the energy required to roast beef under 

 different conditions. 



" The energy required for roasting a rolled rib roast of beef in three types 

 of electric ovens was determined for oven temperatures from 100 to 180°. The 

 most economical temperature for preparing rare and medium-rare roasts was 

 found to be 100° in each oven. For well-done roasts 120" is the most eco- 

 nomical temperature." 



A series of experiments were also carried out on the baking of biscuits, 

 bread, and sponge cakes, in order to determine the range of temperature in 

 which each of these could be most satisfactorily and at the same time eco- 

 nomically baked. Curves are given which show the effect of oven temperature 

 on the time of baking and the percentage of loss in weight and the energy 

 required to bake each article under different conditions. 



" The range of oven temperatures for baking biscuits was found to be from 

 200 to 240°. Starting with the oven at the required temperature, the energy 

 used in making biscuits is practically the same for all oven temperatures. If 

 it is necessary to heat up the oven from room temperature, the most economical 

 oven temperature is the lowest which will give satisfactory results ; i. e. 

 about 200°. 



" The range of temperatures for baking a small-sized loaf of bread was 

 found to lie between ISO and 240°. Starting with the oven at the required 

 temperature, the most economical temperature for baking bread is between 220 

 and 240°. When preheating is included, the most economical temperature for a 

 small-sized loaf was found to be between 200 and 215°. 



" The range of temperature for baking sponge cake was found to lie be- 

 tween 170 and 190°. For baking sponge cake the most economical oven tem- 

 perature is the highest temperature which will give satisfactory results; i. e., 

 about 190°. . . . 



" For baking at the higher temperatures a heating element in the upper part 

 of the oven is necessary to get the best results. Without the upper heating 

 coil the bread, cake, or biscuits will burn on the bottom before they are satis- 

 factorily browned on top. For the lower temperatures this upper coil is 

 unnecessary." 



It was also a feature of the experiments to determine the most economical 

 thickness of heat insulation. It was concluded that " with electricity at 5 cts. 

 per kilowatt hour and allowing an interest and depreciation charge of 25 per 

 cent, the most economical thickness of kieselguhr insulation was found for 

 domestic use to lie between 3 and 4 inches." 



In conclusion the author emphasizes the importance in electric cooking of 

 accurate temperature measurements, adequate means of controlling the tem- 

 perature of the food, and the formulation of definite rules or directions for the 

 cooking of each article. A number of suggestions are given for the construction 

 and operation of electric ovens to secure the best results. 



Nutritional physiology, P. G. Stiles {Pliiladelphia and London: W. B. 

 Saunders Co., 1916, 2. ed., pp. 288, pis. 4, figs. 19). — The first edition of this 

 book has been previously noted (B. S. R., 28, p. 763). 



Hiinger and food, G. J. Peirce {Sci. Mo., 2 {1916), No. 2, pp. 181-188) .—This 

 article considers some economic aspects of the food siipply. 



The amino-acid niinimum for maintenance and growth, as exemplified by 

 further experiments with lysin and tryptophane, T. B. Osborne, L. B. 

 Mendel, et al. {Jotir. Biol. Chcm., 25 (1916), No. 1, pp. 1-12, figs. //). — In expla- 

 nation of the fact that adequate growth has never been obtained with rations 

 in which the nitrogenous components do not furnish sufficient proportions of 



