38 ( 1 02) Society for Experimental Biology and Medicine. 



10 (56). "Anew form of float for water or alcohol manom- 

 eters," with demonstration : HAVEN EMERSON. (By in- 

 vitation.) 



The float consists of an aluminium cylinder with very thin wall, 

 supporting a writing arm of fine aluminium wire. For manometer 

 tubing of ^ in. inside diameter, ^ in. or \ in. aluminium tubing 

 2± in. long is used. This is bored out until the walls are suffi- 

 ciently light. In the upper end is forced a solid cap of aluminium 

 with a small hole in the center into which the wire for the writing 

 lever is driven. The lower end is plugged with cork. Both ends 

 are painted over with hot paraffin to prevent leaking. For use in 

 alcohol a somewhat larger tube is necessary. Three crossed hairs 

 held in place across the open arm of the manometer tube by a 

 strip of adhesive plaster keep the writing arm centered with suf- 

 ficient accuracy. 



The value of the float consists in its cheapness, the ease with 

 which it can be made, its very slight inertia, and its convenience in 

 estimating delicate changes in pressure for which a water or alcohol 

 manometer is needed. 



1 1 (57). " Gelatin as a substitute for protein in the food " : 

 J. R. MURLIN. 



In a series of experiments on dogs the starvation nitrogen was 

 first determined during fasting periods. Varying amounts of gela- 

 tin, containing from one fourth to two thirds of this amount of 

 nitrogen were then fed, the remaining three fourths to one third of 

 the starvation quantity being supplied in meat or other proteins. 

 The calorific requirement of the animal, estimated from Rubner's 

 tables, was made up in each experiment with fats and carbo- 

 hydrates. Results show an equal sparing of the body-protein, 

 whether one fourth, one third or one half of the starvation nitrogen 

 was fed in the form of gelatin, the coincident sparing of protein by 

 fats and carbohydrates being the same. When the coincident 

 sparing of protein by non-nitrogenous food was increased by feed- 

 ing a larger percentage of carbohydrates and less fat, the fraction 

 of the starvation nitrogen fed in the form of gelatin could be raised 

 to two thirds, the other one third being fed in meat. Nitrogenous 

 equilibrium was maintained on this diet for several days. 



