110 C. Barns — Compressibility of Hot Water and 



Art. XV. — The Compressibility of Hot Water and its 



Solvent Action on Glass ; l by Carl Barus. 



1. Between 0° and about 63°, the compressibility of water 

 continually decreases. After this, if temperature rises further, 

 the compressibility increases. It was my original purpose to 

 supplement these results by determining the compressibility of 

 water between 100° and 300° ; £>ut I did not get further than 

 185°, for the reason that at this temperature (and obviously 

 much below it) liquid water attacks glass so rapidly as to make 

 the measurements in glass tubes worthless. 



2. The peculiar behavior, in question, has interested many 

 physicists. Grassi 2 was the first to find that the compressibility 

 (/?) of water decreases with temperature, being 50/10 6 at 0° and 

 44/1 6 at 53°. He also observed that the compressibility of 

 solutions is less than that of water. Amaury and Descamps 3 

 substantiate the latter result ; but they only observe at a single 

 temperature 15°, at which /5=45/140 6 . In CailletetV experi- 

 ments carried as far as 700 atm., only a single temperature is 

 given, and the same is true of Buchanan's 5 results. After this 

 the subject was vigorously attacked by Tait 6 and his pupils, at 

 first particularly with reference to the depression of the tem- 

 perature of maximum density of water, nnder pressure. The 

 probability of such an occurrence had been inferred by Puschl 

 and by van der Waals 7 . Cf. G-rimaldi, 1. c. In later experiments 

 Tait 8 studies the thermal relations of the compressibility of 

 water, but only for small ranges of temperature. Further re- 

 sults are due to Pagliani and Palazzo 9 working with mixtures 

 of water and alcohol, but more directly to Pagliani and Vicen- 

 tini. 10 These observers corroborate Grassi' s work, and find 

 that water shows minimum compressibility at 63°. Grimaldi 11 

 critically reviews the maximum density experiments of Puschl, 

 of van derWaals, of Marshall Smith and Omond, and of Tait. 



1 This paper will be recognized as part of the work suggested "by Mr. Clarence 

 King. 



2 Grassi : Ann. de eh. et de phys.. (3), xxxi, p. 431, 1851 ; cf. Wertheim : ibid. 

 (3) xxhi, p. 434, 1848. 



3 Amaurv and Descamps: C. R., lxviii, p. 1564. 1869. 

 4 Cailletet: C. R., Ixxv, p. 77, 1872. 



5 Buchanan: Nature, xvii, p. 439, 1878. 



6 Tait: Proc. Roy. Soc. Ed., xi, p. 204, 1881; Marshall, Smith and Omond: 

 ibid., xi, pp. 626. 809, 1882; Tait: ibid., p. 813; ibid., xii, 1882-83, p. 226; ibid., 

 xiii, p. 2, 1884-85. 



7 Vander Waals: Beiblatter, I, p. 511, 1877. 



8 Tait: Proc. Roy. Soc. Ed, xii, p. 45, 1882-83; ibid., p. 223; ibid., 1883-84 

 p. 757. 



9 PagliaDi and Palazzo: Beiblatter, viii, p. 795, 1884. 



10 Pagliani and Vicentini : Beiblatter, viii, pp. 270, 794, 1884; Journ. de phys., 

 (2) xxx, p. 461, 1883. 



u Grimaldi: Beiblatter, x, p. 338, 1886. 



