Atomic Volume and Specific Gravity. 491 



caused an increase of 29*5, which gives for an equivalent of 

 the salt the volume 59'0, and a specific gravity 2'04'J. 

 ^ Nitrate of Magnesia, MgO, NO5 + 6HO = 128-8.— The 

 fourth part of an equivalent of crystallized nitrate of magnesia 

 (32 "2 grains) dissolved in 1000 grains of water at 60°, with 

 an injcrease of 18*1 and 18*3 in two experiments. 



/ I. MgO, NO5 + 6HO, vol. in solution 73-2 



':!fYlrIIj')if;/(,f;V).j^!: "ih-Ur.i." ■"■: ... 72*4 



•: ■>-j;7^toj.;Hi*n;MHH»| in l;,-.Mean . . 72*8 



The same quianntyWirbwn' into turpentine produced an 

 increase of 22*0, which gives for the volume of an equivalent 

 of the salt 88*0, and for its specific gravity 1"464. 



Nitrate of Bismuth, BiO, NO5 + 3HO = 160-33.— This 

 salt, being decomposed when thrown into water, is not fitted 

 for determining volume by solution; but when 80*16 grains 

 were thrown into turpentine, the increase was obtained in two 

 experiments of 29-2 and of 29-4. 



! Sp.gr. 



I. BiO, NO5 + 3HO, vol. of salt 58-4 ... 2-745 



II. ... ... i^'J'. ... 58;^ ... 2-727 



Mean . . 58-6 ... 2-736 



Basic Nitrate of Mercury, 2HgO, NO5 + 2HO = 291-0. 

 —This salt cannot be dissolved in water without the forma- 

 tion of a subsalt, unless the water is used in small propor- 

 tion ; it is therefore unfitted for our experiments, as far as 

 regards the volume in solution. On immersing 68-7 grains 

 ii^ turpentine, an increase of 16-2 was obtained in two suc- 

 cessive experiments. This gives 68*6 as the volume of the 

 equivalent, and a specific gravity of 4*242. 



Basic Nitrate of Lead, 2PbO, NO5 = 277-72.— This salt 

 is so insoluble, that it is difficult to determine its volume in so- 

 lution with any great degree of accuracy. The sixteenth part 

 of an equivalent dissolved in 1000 grains of water gave an 

 increase of 2*6, which seems to indicate a volume of 9 x 5. 



69*43 grains, being immersed in turpentine, gave an in- 

 crease of 12*3 in several experiments. 



Sp. gr. 

 Basic nitrate of lead, vol. of salt 49-2 ... 5-645 



The same multiple relation of 9 is carried through all the 

 salts of this class dissolved in .water. The divisor for the 

 solid volume is, however, different from the salts of the pre- 

 vious sections. Exceptional cases were pointed out in their 

 examination, in which 9*8, or the volume of ice, became the 

 divisor; and in the present group of salts we observe a won- 

 derful uniformity in this respect. 



2K2 



