R. J. Southworth—Solutions of Hydrated Salts. 399 
induced me to propose a new name, Aglatte (Engineering and 
Mining Journal, April 7, 1877), but I have since inclined to 
the belief that the material is the same as that first studied by 
Shepard and Burton. It is therefore now presented as an 
independent species, under the original name, wheres eos but 
it seems worth while to retain the name aglaite for application 
to the peculiarly brilliant and micaceous variety foun 
Goshen. In the coming volume of the Annals of the New 
York Academy of Sciences, I shall give a full discussion of 
Art. LI. —The relations of the Volumes of Solutions of Hydrated 
Salts to their Water of Composition ; by RicuMoNnD J. SouTH- 
wortH, M.D. 
THE object of the experiments, the result of which is stated 
in the accompanying table, was to test this 
heorem: If a hydrated salt be dissolved in a given volume of 
water, the volume of the solution will exceed the original volume of 
the water by a bulk equal to the bulk of saline water contained in 
the salt dissolved. 
e expression saline water is used here to signify all the 
molecules of water contained in the salts, whether they exist in 
combination as bases, or as water of crystallization. First, the 
weight in grams of the salt used that contained one cubic cen- 
timeter of water in its composition was determined by dividing 
the atomic weight of the salt by the atomic weight of its saline 
water, both weights being expressed in grams, the quotient 
gave the weight, having one cubic centimeter of saline water. 
As an example: Ferrous sulphate (FeSO, 7H,0) has an atomic 
weight of 278. Its 7 molecules of saline water have an atomic 
weight of 126. 22% grams=2-206 the weight of this salt hav- 
ing one cubic centimeter of water in its composition. 
Second: The quantity of salt determined by this method to 
contain one cubic centimeter of saline water was weig to 
the nearest centigram, and then dissolved in 90 c.c. of water in 
a graduated tube of 100 cc. capacity divided in one-half cubic 
centimeters. For instance, 220 grams of FeSO,, 7H,O, were 
issolved in 90 cc. of water at the temperature of 155° Centi- 
grade when the volume of the solution equalled 91 ¢c.c.: 2:20 
grams more of the salt were added to this solution, and the vol- 
ume rose to 92 ec. This process was continued till 22:06 
grams of the salt, containing 10 ¢.c. H,O, were dissolved in 
90 c.c. of water, when the volume of the solution reached 100 
