Annual Report of the Board of Regents of the Smithsonian Institution Volume 1 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 edition. Excerpt: ...the density is 1.24. Hence its atomic volume is less than 14. The density of liquid nitrogen at--146.6, the pressure of its saturated vapor being 322 atmospheres, was found to be 0.4552; while at--793, under a pressure of one atmosphere, the density was 0.83; and at--202, with a pressure of 0.105 atmospheres it was 0.866. The atomic volume is then about 15.5. Its expansion coefficient is 0.0311 at--153.7, 0.007536 at-193, and 0.004619 at--202. Atmospheric air on compression behaves like a mixture whose components followed different laws of liquefaction; and when liquified its composition changes with change of temperature or pressure. The value of the density found by experiment at--146.6 and under a pressure of 45 atmospheres was 0.59. Calculation gives 0.60 as the value obtained from liquid oxygen and nitrogen. (0. R., May, 1886, en, 1010.) Nilson and Petersseu have described a new method for determining the vapor density of volatile substances and at the same time the temperature of the experiment. Four determinations with this apparatus, of the density of the vapor of glucinum chloride at temperatures varying from 1080 to 1502, gave 2.77 as the mean value. (Ann. Chiin. Phys., December, 1886, VI, ix, 554.) Nodon has utilized the hygroscopic properties of gelatine in the construction of a recording hygrometer. A layer of this substance is fastened to the outside of a helix of Bristol board, the inside being protected by a non-hygroscopic varnish. An increase in the atmospheric moisture expands the gelatine and unrolls the helix, as a change of temperature does the helix of Breguet's thermometer. The result appears within ordinary limits to be independent of temperature. The hygrometer consists of four such helices grouped in pairs upon the same...