and Saline Solutions at High Tempei-atures. 



89 



•997696+-00Oll0U+0000O343<2. 



= -9977 +000123/ +-00000330/2. 



= -9991 + -00021 5 < + 0000025 1<«. 



: -9997 +000326# +00000141<2. 



= -9999 +000359< +00000139/2. 



= 10000 +000397/ +-00000127/2. 



= 9999 +000343/ +00000160/2. 



Water according to Kopp's experi- "I y __ 



merits J 



Water according to my own experi- \ y __ 



ments J 



Water with 10 per cent, of chloride of \ y . 



potassium J 



Water with 25 per cent, of chloride of 1 y ^ 



potassium J 



Water with 12^ per cent, of ditto, and "1 y 



12^ per cent, of chloride of sodium j 

 Water with 25 per cent, of chloride of \ y 



sodium J 



Water with 25 per cent, of anhydrous 1 y 



sulphate of soda J 



These various saline solutions, therefore, indicate much the 

 same facts. The presence of the salt in all cases tends to make 

 the expansion of the liquid more uniform, increasing the value of 

 the coefficient of t, but diminishing that of i^; the extent of this 

 influence varying with the amount and nature of the salt. The 

 discussion of this fact appears to lead to some curious results. 



According to the experiments of myself and others, the mean 

 specific gravity of chloride of potassium is about 1-94. Hence 

 the relative volume of one part by weight to three of water would 

 be -1466 to -8534; and, if there were no change of dimensions 

 when the two mixed together, on solution the united volume 

 would be 1-0000, and the specific gravity should be 1-138. I 

 however found, by experiment, that the specific gravity is really 

 1-1745; thus indicating that the united volume is only -969, 

 and that there is a contraction of one or other of the consti- 

 tuents equal to 3-1 per cent, of the whole bulk. Hence 1-000 

 part of the solution would contain about -880 part of water and 

 •152 part of KCl, making a total volume of 1-032, but contract- 

 ing on being mixed to 1-000. Now, if we calculate what would 

 be the volume of this -88 part of water at various temperatures, 

 as ascertained by actual experiment, supposing it to exist in a 

 free state, we obtain as shown in the following Table ; and deduct- 

 ing these various volumes from the actual volumes of the saline 

 solution as found by experiment, we ascertain what is the difi"er- 

 ence in the total bulk made up by the chloride of potassium. 



