1835.] Improvements in Science. 109 



Atmospheric Air. — According to Berthollet, by the usual 

 phosphorus eudiometer, the remaining azote is increased 

 by the phosphorus vapour 4 ^ of its volume. To satisfy him- 

 self upon this point, Brunner passed a quantity of atmos- 

 pherical air from a gas holder, first through mercury and 

 chloride of lime, and then through red hot iron filings. 

 The gas thus freed from oxygen was placed over mercury, 

 the temperature and pressure being noted. A stick of dry 

 phosphorus was next allowed to remain for some time in 

 the gas, but produced no change in its volume. Some- 

 times, after standing many days, a slight dimunition took 

 place, but never amounting to 1 per cent., which was 

 ascribed to the admission of a small portion of oxygen. 



Tralles, from theoretical views, calculated that the quan- 

 tity of oxygen in atmospherical air diminishes with the 

 height, and that at the surface of the sea, air contains 



21*00 per cent. 

 1000 feet above the sea 20*90 

 8000 Do. - - 20*22 



Saussure found the quantity less upon the hills than in 

 the vallies, (1*25 less) by means of Priestley's eudiometer. 

 Berger, with sulphuret of potassium, phosphorus, and 

 nitrous oxide, estimated the proportion at between 20 and 21 

 per cent. 



Configliachi observed that with phosphorus the propor- 

 tion of oxygen was smaller below 50° than above 64£°. 



The mean of 14 experiments by Brunner gives for the 

 proportion of oxygen in common air, determined by means 

 of phosphorus, 20*915 per cent. 



The smallest quantity obtained was 20*75, the temperature 

 of the residual azote being 50° F, and the pressure 555*9 

 millimetres, and the greatest result was 21*11 when the 

 thermometer was 53f° F, and the barometer at 556.0 mill. 

 Both experiments were made about 7 a. m. (Pogg. xxxi. 1.) 



Compounds of Carbon and Hydrogen. — Dumas and Boullay 

 have endeavoured to prove, by numerous analyses, that, 

 1. A compound of carbon and hydrogen acts as a base, 

 analogous to ammonia; 2. That alcohol and ether are 

 hydrates of this body ; 3. That carbohydrogen forms with 

 hydracids, anhydrous compound ethers; and 4. That the 

 same body with oxygenacids forms compound ethers con- 

 taining an atom of water. 



