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» and Equivalent Volumes of some Mineral Species. 207 
upon the heat evolved in fusion and solution, that the equivalent 
weights of crystallized salts are multiples of those deduced from 
the analysis of these same salts in solution. 
n order to establish a starting point, it will be necessary to de- 
termine the volumes of some species, whose combining propor- 
tions are known to be very high in proportion to their densities. 
Ferrocyanid of potassium, C12NscFe:K., 6HO, has an equiva- 
lent weight of 422°8 and a density of 1-832, giving 230 for its 
volume; milk-sugar, C2:H» Oz, has an equivalent of 360, wit 
a density of 1:534, and a volume of 234; and cane-sugar, C24 
H22O22 gives 342, with a density of 1-593, and a volume of 215. 
These species approach to andesine in equivalent volume. The 
formula of the combining proportion of piperine, deduced from 
its platinic chlorid, is established by the researches of Wertheim, 
as corrected by Gerhardt, to be C7oHscN:Oro, to which in the 
monoclinic crystallized alkaloid, H»Oz is to be added, giving an 
equivalent weight of 582. I obtained for its density in three 
experiments with a carefully purified specimen, 1-238, 1-244 and 
1-250, giving a mean of 1-244, which corresponds to an equivalent 
- volume of 467-8, or double that calculated for andesine, the soda 
salts, and other prismatic species above. We may therefore double 
the equivalents of these species, as well as those of leucite and 
the alums. Their formulas and equivalent volumes will then be 
ws: 
Alum, SsO24 (aleK2H4s)Ose 5480 
ea-salt, Na2oCl2o0 526°0 
Chlorid of potassium, | K14Clia 5314 
Leucite, Si1eO4s (alisKe) O24 534:0 
Andesine, Si1¢Oas (al1s NasCa2K)O2¢ 460°'8 
Piperine, Cz2Hs6N2010, H202 467'8 
n(C2H-), and an examination of some oxyds crystallizing in the 
other species as franklinite, chromoferrite, martite, have a similar 
CuO, with an equivalent weight of 39-7, and a mean density 
99- and a density of 3-7, has a volume of 27°, giving for Asx 
Ocomase0Qso, a volume of 540. eh 
