202 F. W. Clarke—Specific Gravity Determinations. 
The double bromide of mercury and potassium was also pre- 
pared and examined by Mr. Beamer, both in the hydrated and 
the anhydrous state. For the salt HeBr,, KBr, he found 4°412, 
17°-2; 4419, 24°5; 43996, 20°5. For the hydrated salt, 
HgBr, . KBr. H,0O, as a mean of six concordant determinations 
taken between 20° and 24°, he found a sp. gr. of 3°867. The 
ieee bromide used in these preparations gave a sp. gr. of 
2:°712; 12°°7.* 
Mr. Dear also redetermined the — gravity of the 
curious double salt (NH,),Cr,0,.HgCl,.H,O, finding it to 
be 3329, 21°. 
Mereuric iodide and a — of a salts were determined 
by Miss Mary E. Owens. a ee mean of seven experi- 
ments between 10° and 19°, j is 565 Bio: 
For the double eo Ruse Hgl,).3H,O, the sp. gr. is 
4-289, 23°°5; and 4254 
For the ‘iodide of “a ee and sable agers ne 
N(CH,),1.HgI,, were found the values 3-968, 24°; 3°976, 
23°; 3-97 1, 24°; 4:008, 23°-2. The iodide of tetramethyl- 
ammonium itself, well crystallized, ier found by Miss Owens 
to have a sp. gr. of 1 Loah. 1c"; 1831, 19°°5. 
Cadmium chloride and some of its double compounds were 
examined by Mr. Walter Kni 
The anhydrous chloride, CaCl, ga gave as a mean of three 
determinations the value 3-93 8, 23° The hydrated salt, 
CdCl, .2H,O, gave a sp. gr. of 3°339, 18°2; 3320, 23°°2 ; 
3314 , 28°" 
The double chloride of cadmium and strontium, 2CdCl, . 
SrCl, .7H,0, in fine erystals; as a sare of three experiments, 
2°952, 24°°5; and 2-966, 25°-2. 
Several salts of acids belonging i in the xanthic acid — 
were et by students under the direction of Professo 
arder; and of these, APS well are seannple! 
had their specific gravity determined. 
otassium pieiesidensi ianearbonete KOH, « vad 
pes Mr. E. P. Bishop, has a sp. gr. of 1°7002 ne 16754 
Potassium et ee was determined by Miss 
Helena Beadle and by Dr. rt. Miss Stallo found the 
sp. gr. to be 15564, 18°-2; oe mae 21°5. Dr. Geppert’s 
determination gave re Bee a 
* a ge mean value for hy salt is 2690, Pogg. Ann., 1859. 
Filhol, Ann. d. Chim. et Phys. III, xxi, 1847, gives 6-250. 
Spe es a sp. gr. of "F6254, 12°. long. 1860. 
§ Topsoé, Chem. Centralblatt, iv, 76, found 2 
