and Attached Water. 55 



Hence it appears that the composition of the successive crops 

 of cryohydrate is nearly unchanged. The later the crop, the 

 poorer is it in water and potassium and the richer in ammo- 

 nium. And the increase in the ammonium is greater than the 

 decrease in the potassium. The same ratio of the same chlo- 

 rides, when used as a cryogen, gave -—18°. Accordingly 



o 



The cryohydrate of KC1 solidifies at — 1T4. 



„ NH 4 C1_ „ -15 



.. „ equiv. mixture „ — 17 



and 



As a cryogen KG gives — 10*5 



„ ' NH 4 C1 _ „ -16 



„ equiv. mixture „ —18 



§ 114. Mixed Nitrates of Barium and Strontium as Cryo- 

 hydrates and Cryogens. 



7'05 grms. of Sr2N0 3 , 

 and 



8-70 grms. of Ba2M) 3 



were dissolved, mixed, and allowed to evaporate to incipient 

 crystallization. At — 1°*2 a cryohydrate began to form; and 

 the whole was solid at — 4°*3. Employed as a cryogen, the 

 same mixture of salts gave — 5 0, 8. We have therefore 



o 



The cryohydrate of Sr 2 N0 3 solidifies at . —6 

 „ . Br 2 NO, » . ; • -0-8 

 „ „ equiv. mixture solidifies at —4*3 



and 



o 



As a cryogen Sr 2 N0 3 gives ... — 6 



Ba2N0 3 „ L -, i - -0- 



„ equiv. mixture gives . —5* 



§ 115. Mixed Chlorides of Barium and Strontium as Cryo- 

 hydrates and Cryogens. 



6-933 grms. of BaCl 2 

 and 



5-283 grms. of Sr Cl 2 , 



both salts having been gently ignited, were dissolved, mixed, 

 and evaporated to saturation. On cooling, a large quantity of 

 transparent salt fell out above 0°. At about —10° a cryohy- 

 drate began to form, and the whole was nearly solid at — 13°-5 

 to —14°. A small portion, however, remained liquid to 

 -18°. 

 Mixed with snow, the above salts in the above proportion 



