192 ANNUAL OF SCIENTIFIC DISCOVERT. 



yeast, which had changed itself into sugar. If this were true, 

 the cellulose ought to disaj^pear; it remains behind, however, 

 unaltered. During the formation of alcohol no trace of ammonia 

 is generated. As some of the most remarkable products of this 

 vital process, Liebig mentioned leucine and tyrosine, and a nitro- 

 genous substance containing sulphur. — Chemical News. 



CHEMICAL ANALYSIS OF SANDSTONES. 



Dr. Phipson has examined specimens of sandstones of different 

 geological formations, to ascertain if it be possible to determine 

 the particular strata to which a sandstone belongs by the nature 

 and proportions of the substances which it yields to boiling hydro- 

 chloric acid. His analyses appear to show that : 1. Tertiary 

 sandstones yield to the acid, principally lime and peroxide of 

 iron. 2. New red sandstones will yield peroxide ot iron, lime, 

 and magnesia, and the latter will be found almost invariably in 

 the proportions necessary to constitute dolomite. 3. The sand- 

 stones of the coal measures give a notable amount of protoxide 

 of iron and some manganese, as well as lime and magnesia. 4. 

 The old red sandstones give peroxide of iron, lime, and magnesia, 

 but the lime is in excess, and not in the proportion to form dolo- 

 mite. 5. In the older sandstones, talc or silicate of magnesia 

 appears, with or without the ingredients above named. — Chemical 

 News. 



PREPARATION OF OXYGEN FROM THE AIR. 



M. Boussingault, in 1852, found that, on passing a current of air 

 over baryta heated to dull redness, oxygen was subtracted from 

 the air, and binoxide of barium formed ; and that, upon then 

 raising the heat to bright redness, the oxygen was set free so easily 

 that it might be first absorbed and then evolved ad infinitum. 

 M. Gondolo has recently made some improvements in the details 

 of the process, which permit the preparation of oxygen in this 

 way on a manufacturing scale. He substitutes wrought or cast 

 iron tubes for porcelain ones, coated internally with magnesia, 

 and externally with asbestos, so as to diminish the porosity of the 

 tube and the consumption of fuel. The tubes are arranged in a 

 brick furnace, with dampers, by which dull or bright redness may 

 be obtained at will. To the baryta a mixture of lime, magnesia, 

 and a small quantity of manganate of potash is added ; this pre- 

 vents fritting of the material. M. Gondolo says that he has made 

 122 alternate operations, and that the atmospheric oxygen and 

 nitrogen are easily separated upon an industrial scale. The ap- 

 paratus has been at work 6 months, and fulfilled its purpose com- 

 pletely. — Quart. Journ. of Science^ July, 1868. 



