THE 

 LOXDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE/ 



[FOURTH SERIES.] 



JANUARY 1875. 



I. On Salt Solutions and Attached Water. 

 By Frederick Guthrie*. 



§ 1. ri^HE interesting paper read to the Physical Society of 

 J- London by Dr. J. Rae, the arctic explorer, on the 

 comparative saltness of freshly formed and older ice-fioesf, in- 

 duced me to examine some of the physical properties of brine 

 and some other of the aqueous solutions of the salts of the sea. 

 This examination has extended itself to some other salts ; for 

 before attacking the problem of the freezing of sea-water, the 

 composition of which may be little less complex than that of the 

 earth itself, it seemed advisable to enrich our knowledge of the 

 properties of the solutions of some of its more abundant consti- 

 tuents in the separate form. Some of the experimental results 

 unexpectedly opened so wide and fascinating a field of inquiry, 

 that I have been compelled to make some sort of survey of it ; 

 and though the results there gathered are of sufficient interest 

 to be considered by themselves as physical facts, they will assu- 

 redly also be concerned in the establishment of a sufficient 

 theory of thalattology. 



Chloride of Sodium. 



§ 2. Being fortunately in possession of a large quantity of 

 extremely pure rock-salt in fine crystals, I satisfied myself by 

 the spectroscope of the absence of potassium and lithium. By 

 the usual tests, magnesium and sulphuric acid were also shown 

 to be absent. A determination of the chlorine agreed so closely 

 with the theoretical quantity that not more than 0*2 per cent. 



* Read before the Physical Society, November 7,1874. Communicated 

 by the Society. 



T Proc. Phys. Soc. May 9, 1874. Phil. Mag. July 1874, p. 56. 

 Phil. Mag. S. 4. Vol. 49. No. 322. Jan. 1875. B 



