Percentage of 

 Li 2 + 3H 2 0. 



Li 2 + 3H 2 per 

 100 of Water. 



16-02 



19-07 



18-63 



22-89 



18-85 



23-23 



HYDRATES AND CARBONATES OF THE ALKALI-METALS, ETC. 435 



weighed. The residual solution served for the determination of the lithia as sulphate. 

 Three such experiments were made. The records of the first were as follows : — Weight of 

 solution taken =6*395. C0 2 in the same =6*0 mgrm. = 4*1 mgrm. of Li 2 O = 10*l of 

 Li 2 C0 3 . Hence corrected weight of hy drate-solution = 6' S9 5 — 0"0101 = 6*3849. Sulphate 

 of lithia obtained 1*354 grm. = 0*3695 of Li 2 0. Hence Li 2 present as hydrate = 0*3654 ; 

 and percentage of Li 2 in the saturated solution = 0*3654 x 100-*-6-3849 = 5*724, corre- 

 sponding to 16*016 of the hydrate Li 2 + 3H 2 and 83*984 grm. of water ; or 19*073 grm. 

 of Li 2 + 3H 2 per 100 grm. of water. 



Experiments II. and III. were carried out similarly, except that the lithia solution left 

 after expelling the C0 2 was fractionated with the balance, to obtain duplicate determina- 

 tions for the lithia. In both cases the two values for the lithia agreed very well with 

 each other. The final results were as follows : — 



In the Solution saturated at 19°*4. 



Experiment. Percentage of 



I. . . 5-72 



II. . . 6-66 



III. . . 6*74 



Excluding No I. as being probably infected with an unobserved error, we have as a 

 mean of II. and III. — 



6*70 18-74 23-06 



Experiments at 0°. — In the first two experiments (I. and II.) portions of the solution 

 prepared at 1 9° *4 were kept in an ice-bath for about twenty-four hours, and quantities of the 

 clear liquors drawn off for the determination of the C0 2 and Li 2 0. In Experiments III. and 

 IV. 10 c.c. of boiled-out water were placed in a glass-stoppered 80 c.c. bottle, and next kept 

 in ice for half an hour, to make sure of everything being at 0° ; a sufficiency of previously 

 cooled-down crystals was then added, the bottle stopped up, the stopper tied over with 

 vegetable parchment, and the bottle immersed in an ice-bath provided with a lid, 

 and entirely buried in a mass of ice contained in an outer vessel. After forty-five hours' 

 standing the ice in the inner bath was still in its original condition. A quantity of the 

 clear liquor was drawn off with a cooled-down dry pipette, weighed and analysed as 

 usual. The results were as follows : — 



In the Solution saturated at 0°. 



Experiment. Percentage of 



I. . . 5-77 



II. . . 5-61 



III. . . . 5-85 



IV. . . 6*32 



Percentage of 

 Li 2 + 3H 2 0. 



Li 2 + 3H 2 per 

 100 of Water. 



16*16 



19-28 



15-69 



18-61 



16-36 



19-56 



17-69 



21-49 



