146 Scientific Intelligence. 
9h On the Behavior fl a acid in the Organism of Birds. 
FFE has taken up anew the question of the ¢ change which 
“ins acid undergoes in the organism of birds, first investigated 
y Meissner and Shepard. He confirms the result of these latter 
chemists that no isopiiein acid is geen but that an acid is ex- 
creted which like hippuric acid is a paired benzoic acid. To this 
acid he gives the name ornithuric ary e prepares it by ex- 
tracting with alcohol the fresh excreta of hens fed on benzoic acid, 
evaporating the alcohol, = ew ing again with hot absolute alcohol, 
and evaporating. ame? sre dedi aegis liquid is mixed wit 
thuric acid separates in crystalline ‘ikea having when pare the 
empirical formula C,,H,,N,O,. Boiled with hydrochloric acid it 
gives benzoic acid and a new base C (NH, ):0» inn 
acid.— Ber. Berl. Chem. Ges., x, 1925, Nov. . B 
9. Le Sage 8 Theory of Gravitation ; J by ae Seeds LLD., 
F.R.S.—Le Sage’s Theory of Gravitation is at present exciting a 
good deal of attention among physicists. ag is perhaps to a 
considerable extent due to the fact that some of the — 
arbitrarily assumed by Le Sage in his ent othesis, have 
ogc to follow as necessary consequences from the kinetic ene 
e 
one case at least he seems to me to have failed.* It isa necessary 
condition of Le Sage’s theory, in order that gravity may be pro- 
portional to mass, that the total volume of the free spaces In a 
apa in the form of interstices between the molecules a 
t compared with the total volume of matter containe 
- fiolbenles themselves. This condition of free interstices Mr. 
Preston considers to be satisfied by assuming the molecules to be 
small as compared with their mean distances 
Were we at liberty to make any assu ssumptions we chose in refer- 
ence to the smallness of the molecules of matter and their distance 
* In an interesting article on Kinetic Theories of Gravitation by Mr. W. B. 
ttayslot-pabiiahed in the Smithsonian Report for 1876, he lays down six funda- 
characteristics of of gravitation with which every theory, he says, must 
six requirements, Le Sage’s theory he maintains satisfies but 
