102 NOTES. 



Nutritive Value of Sugar. (By N. Zuntz, Omn. Cent?-., 

 1895, I., 691 — 692, from Zeit. ver. Riibenzuck., 1894, 64, 71). — By 

 causing a dog to mount continuously a plane inclined at 10" to 

 the horizon, and analysing the expired air, it is possible to calcu- 

 late the amount of oxygen used per kilogram -metre of work done, 

 and also the quantity of heat produced by the combustion in 

 which this oxygen took part. The amount of oxygen used per 

 kilogram-metre of work done was found to be, for a diet of lean 

 meat, 0-57 c.c. (o'58 Cai.) ; fat, 0*53 c.c. (2 -43 Cal.) ; cane sugar, 

 0.54 c.c. {2'58 Cal.). Sugar, fat, and lean meat have thus about 

 the same power of enabling physical exertion to be sustained. 

 The efficiency of the animal body, considered as a machine, was 

 found to be about one-third, whereas with steam-engines only one- 

 twentieth to one-fifth of the energy of the fuel is obtained as 

 mechanical work. 



Can Non-Leguminous Plants Fix Free Nitrogen ? By 

 F. Nobbe and L. Hiltner {Landw. Ver sticks- Stat., 45, 155 — 159). 

 — After it was established that LegunimoscE, when suitably infected 

 with nodule bacteria, have the power of assimilating free nitrogen, 

 the authors showed that under similar conditions the same holds 

 good with Elceagnas and with the white and black alder. Podo- 

 airpus, a conifer, which also has root nodules, seems likewise to 

 have the power of fixing nitrogen. The same property has recently 

 been frequently attributed also to non-leguminous plants, which 

 have no root nodules, the evidence being that the final nitrogen in 

 the plants and soil was greater than the initial nitrogen in the 

 seeds and soil. 



Heat of the Sun. — In an article in the June (1895) number 

 of the Astrophysical Journal by H. Ebert, he concludes that the 

 temperature of the interior region of the sun is in round numbers 

 40,000*^ C. This is in good agreement with values previously 

 determined by others. 



We shall be pleased to insert Exchange Notices without charge 

 fojr our readers. — Editor. 



