26 



MACGEEGOE ON DENSITY AND 



Thus in the case of Sohiff's observations also, the formvila holds up to between 2 and 

 2'5 per cent. 



Iron Sulphate. — FeSO^. 

 Observer : The author. 



Température: 20°C. 



Formula: D,o = 0-99827 + 0-0099486 p. 



For solutions of Iron Sulphate therefore the above formula holds u^) to and beyond a 

 concentration of 2'6 per cent. 



Observer: Gerlach.' 

 Temperature : 18°C. 

 Formula : Dj, = ■ 99866 + ■ 0098427 p. 



Copper Sulphatk — CuSOj. 



Thus according to Gerlach the limit of concentration within which the above formula 

 applies is somewhat less than 2 per cent. 



Observer : Grotrian. - 



Temperature: 18°C. 



Formula .- D,s = - 99866 + - 0097329 p. 



Cadmium Sulphate.— CdSO^. 



' Fi-es. Zeitschr. f. analyt- Chem. viii (1869) p. 279; Landolt u Bornstein's Pliys-Ohem. Tabellen p. 147- 

 - Wied. Ann. xviii (1883) p. 191. 



