Atomic Volume and Specific Oi'omty. SOHK 



grains in turpentine, was an increase of 18*55, which gives. 

 37*1 for the vohime of the equivaleat,>-and'j2f68Siaa theispei^ 

 cific gravity of the salt. iu'r-'^nloq \-) ni?.frffjfOjrnn?l rnVV 



Sesquichr ornate of Po^«*/<, 2 KO, 3 CrOg = 251 'OD.— This 

 salt, which will be described in a future communication by 

 one of us, is obtained by boiling a solution of bichromate of 

 potash with an excess of finely pounded litharge. The oxide 

 of lead removes only one-fourth of the chromic acid of the 

 bichromate, and the solution on cooling deposits the sesqui- 

 chromate in flattened pinsms of a paler but more resplendent 

 colour than the bichromate of potash. On dissolving the, 

 fo,urth part of an equivalent, 62*77 grains, in 1000 grains of 

 water, the increase in four experiments at 58" was exactly 

 18*0 ; this gives 72*0 as the volume of the equivalent in so^qr-f 



tion. ... '-tii.i 



The mean of six experiments, placing the fourth of an 

 equivalent, 62*77 grains, in turpentine, was an increase of 

 23*7, which gives 94*8 as the volume of the equivalent, and 

 2*648 as the specific gravity of the salt. 

 c BicM'omate of Potash, KO, 2Cr08 = 151*70. — ^n ^^- 

 solving 76 grains of this salt in 1000 grains of water, an in-, 

 crease of 22*5 and 23*0 were obtained in. t\vo experiments at,' 

 V^j ?:ftriH? >o bjRjigni ^gilif^ai oriJ 'to mora ;)ftJ i^/vg ^s'loio'iadi 



II. ... /llfijjbi/iluii Jflamri3c|k&&loB9 ^nidiioa 



in \mu biDi, oxmt'iiij ;iiiT — .<M^f=^iP*J^P ^S^ osroonAO 



~Jd,o|J>roB ohfuiylL'^.^'nlbj'if: '<^- h'^Qj^'^l^Q 8R"'". K'inflmhsqzfi.ii.ro 

 Half an equivalent of the salt, 75'84 grams, iramersed m 



turpentine, gave an increase, the mean of ten experiments, of 



28*9, which gives 57*8 as the volume of an equivalent, and 



2*624 as the specific gravity of the salt. 



Terchromate of Potash, KO, SCrOg = 203*92.— This salt 

 was obtained by mixing a solution of bichromate of potash 

 with nitric acid and crystallizing. On dissolving 51 grains 

 of the salt in 1000 grains of water, an increase was occasioned 

 of 18*0 at 60°; this gives 71*9 as the volume of the equiva- 

 lent in solution. . . 



On immersmg 50*98 grams m turpentme, the increase was 

 19*3 in two experiments, and 19*0 in a third trial. 



I. KO, 3Cr03, vol. of salt 77*2 ... 2*641 

 II. ... ... 77'2 ... 2*641 



■ villi -cU' '.' &?.C910 



Bichromate of Chloride of Potassium, KCl + 2Cir03 =3 

 179*08. — The fourth part of an equivalent, 44*77 grains, being 



