and Attached Water, 267 



grms. gave 1*4735 BaCl 2 , or 24*0 per cent. The first of these 

 shows the formula 



BaCl 2 -f37*8H 2 0. 

 § 79. Chloride of Strontium, — This salt forms a cryohydrate 

 at — 17°. Of the final portion, 5-8325 grms. contained 1-6085 

 of SrCl 2 , or 27'57 per cent. The crop before this showed 

 1-3655 grm. of salt in 4*9675 solution, or 27'5 of SrCl 2 . We 

 may therefore deduce the formula 



SrCl 2 + 22*9H 2 0. 



Nitrates of the Alkaline Earths, 



§ 80. Nitrate of Barium. — The cryohydrate of this salt soli- 

 difies from a saturated solution at — o, 8. I have only one deter- 

 mination of its composition ; namely, 3*0370 grms. gave 0*1610 

 of anhydrous salt, which corresponds to 5*30 per cent., and the 

 molecular ratio 



Ba2NO 3 + 259;0H 2 O. 



§ 81. Nitrate of Strontium. — On cooling a saturated solution 

 to —6° the cryohydrate solidifies. Of the last portion, 6*8010 

 grms. gave 1*7675, or 25*99 per cent, of Sr2N0 3 . Of the pre- 

 vious crop of the cryohydrate, 4*6715 grms. contained 1*2105 

 of the anhydrous salt, or 25*91 percent. These determinations 

 concur towards the relationship 



Sr2N0 3 -33-5H 2 0. 



Miscellaneous Cryohydrates. 



§ 82. Sulphate of Iron, — Green vitriol separates from a satu- 

 rated solution at — 2°*2. The next to the last portion of the cryo- 

 hydrate showed the following composition : — 4*7000 grms. gave 

 0*8155 FeS0 4 , or 17*35 per cent. Of the last portion, 4*8140 

 grms. gave 0*8155, corresponding to 16*94 per cent., and show- 

 ing the ratio 



FeS0 4 + 41*41H 2 0. 



Although the solution of this salt was quite clear when her- 

 metically sealed for analysis in a tube containing not more than 

 *5 cubic centim. of air, a considerable deposit of sesquioxide took 

 place. The analysis, therefore, is probably not quite exact. 



§ 83. Chromate of Potassium. — The cryohydrate solidifies at 

 — 11°. Of the last crop of crystals, 3*0690 grms. gave 1*1145 

 anhydrous salt, or 36*27 per cent. Of a previous crop, 5*4775 

 grms. gave 1*9945, or 36*41 per cent. The first indicates the 

 formula 



K 2 Cr0 4 + 18*8H 2 0. 



From § 28 the bichromate has a cryohydrate solid at — 1° and 



T2 



