The Composition of the Atmosphere with Special Reference to Its Oxygen Content (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. 1912 Excerpt: ...so great as to be explainable only on the ground of imperfect technique. Subsequent development of apparatus and method yielded a procedure so accurate that duplicate analyses of each day's sample did not vary from one another by more than 0.02 per cent. On five different days in the fall of 1877 he found 20.89, 20.76,20.96, 20.91, and 20.90 per cent of oxygen, respectively. In 1879, analyses were made in April and May as follows: Apr. 24 21.16 Apr. 27 20.83 Apr. 30 20.83 Apr. 25 20.91 Apr. 28 20.87 May 1 20.82 Apr. 26 20.92 Apr. 29 20.70 May 3 20.55 By means of the improved apparatus, an interesting comparative series of analyses was made, samples of air being collected in July 1883, simultaneously by Professor Hempel in Dresden and Professor E. Hagen on the steamer between Liverpool and New York, all samples being taken at 8 a. m. The results are given in table 39. Table 39.--Determinations of oxygen in atmospheric air, collected at sea and in Dresden. 1 Hempel, Berichte der deutschen chemischen Gesellschaft, 1885,18, p. 267. Using identically the same apparatus, Oettel in Hempel's laboratory determined each day the carbon dioxide and oxygen of Dresden air from October 12, 1884, to December 24, 1884. Oettel's results are expressed in the form of a curve not easily reproduced, but table 40 shows his results from November 8 to 18. The duplicate analyses permit an estimate of the accuracy of the method he used. The figures also show the general extent of the variations he observed in the oxygen and carbondioxide content of the atmosphere. Table 40.--Determinations of oxygen in Dresden air, made by Oettel. A few months later Hempel, in defending the use of potassium pyrogallate from the criticism raised by Kreusler,1 published further experiments on air.2 In ...