78 



WALTER E. GARREY. 



The figures for the depression of the freezing point (A) given 

 In Table I. indicate the wide range in concentrations in sea waters 

 of different localities. 



Table I. 



Sea Water from : 



Naples 



Arcachon 



Pacific Grove, Cal 



Pacific Grove, Cal 



Woods Hole 



Beaufort, N. C. . . 



Helgoland 



In the Kattegat . . 

 Open Baltic Sea . . , 

 Kiel harbor 



Reference. 



Arch. ital. de bioL, 1897, XXVIII., 61. 

 Trav. des Lab. d'Archachon, 1899. 

 Bull. U. S. Bureau Fisheries, 1904. 



XXIV., 429. 

 Biol. Bull., 1905, VIII., 257. 

 Biol. Bull., 1905, VIII., 257, 

 1911. 

 Bio-Chem. Jour., 1908, 269. 



In the following sections further details obtained by the author, 

 by means of the cryoscopic method, are given for sea waters of 

 some American localities. 



(a) Woods Hole. — Determinations made during the summer of 

 1904 have been previously reported (loc. cit., pp. 258-259) show- 

 ing the freezing point to be slightly variable between — 1.805 and 

 — 1.84° C. The average of determinations made the latter part 

 of July of six different years gave an average A = — 1.81° C,. 

 with which, as will be seen from succeeding data, the following 

 solutions are isosmotic: Sodium chloride, 0.52 w; Magnesium 

 chloride, 0.29 m., cane sugar, 0.73 m. "Van't Hoff's solution," 

 made from w/2 stock solutions, had a freezing point of — 1.84° C, 

 this is so slightly In excess of the concentration of Woods Hole 

 sea water that It may be considered Isosmotic with it. This 

 "Van't Hoff's solution" was made up from half molecular solu- 

 tions according to the formula given by J. Loeb, (3) viz : 100 mole- 

 cules NaCl, 2.2 molecules KCl, 1.5 molecules CaCl2, 7.8 molecules 

 MgCl2 and 3.8 molecules MgS04. The traces of bicarbonate 

 and phosphate were omitted from the solution, but when added 

 In optimum amounts {e. g., 1 c.c. N/20 NaHCOs per 100 c.c. 

 solution, as in the procedure of Loeb, p. 35), the solution becomes 

 exactly isosmotic with Woods Hole sea water. 



(&) Pacific Grove. — Green in 1904 made freezing point deter- 



n 



