grams. BaOC0 2 . 



BaO. 



22-1204 gave 0-4271 



or 0-331707 



19-6436 „ 0-3790 



„ 0-29435 



14-7921 „ 0-2924 



„ 0-22709 



36 Frederick Guthrie on Salt Solutions 



— o, 5. At this temperature the cryohydrate is formed, the 

 temperature remaining constant until solidification is complete. 

 The barium was estimated by adding carbonate of ammonium 

 and gently igniting. 



BaO per cent, 

 or 1-4995 

 „ 1-4984 

 „ 1-5352 



The above analyses are of three separate liquid residues after 

 the separation of two crops of cryohydrate in each case. 



The water-worth calculated on the whole three of these 

 results is 565. 



As a cryogen the same temperature ( — 0°*5) was obtained. 

 § 168. Hydrate of Strontium. — On lowering the tempera- 

 ture of a saturated solution of this hydrate, crystals of the same 

 separated until the temperature — o, l was reached ; the cryo- 

 hydrate then formed. 



grams. SrO C0 2 , SrO. SrO percent. 



17-2620 gave 0-0944 or 0*5468 or 0-3838 

 13-5124 „ 0-0774 „ 0-5728 „ 0-4020 



The analyses were of different liquid residues after two crops 

 of cryohydrate had been separated from each. The water- 

 worth derived from the mean of these two analyses appears to 

 be 1463. As cryogens, SrO H 2 O or SrO when mixed with 

 ice did not lower the temperature below 0°. A very slight fall 

 to — o, 09 was obtained on slaking SrO with water and allow- 

 ing it to assume the normal temperature before mixing with 

 ice. Such a fall, however, can scarcely be recognized. 



§ 169. Hydrate of Calcium. — This body, as is well known, 

 presents the very interesting peculiarity of being more soluble 

 in cold than in hot water. On further cooling the solution 

 saturated at a certain temperature above 0°, .one gets an im- 

 perfectly saturated solution ; and on still further cooling, ice 

 appears. But if the solution be kept saturated during cooling, 

 which can be well effected by continued stirring with some hy- 

 drate precipitated by rise of temperature in another quantity, 

 the cryohydrate appears at — o, 15. 



grams. CaO C0 2 . CaO. Ca0 , 



2 per cent. 



22-1094 gave 0*1030 or 0-057630 or 0*26 



23-3498 „ 0-1222 „ 0-068432 „ 0-29 



The analyses were of different liquid residues after two crops 

 of cryohydrate had separated : the mean of these two results 

 corresponds to the relation 



CaO + 1116 H 2 0. 



