108 Mr. Richard Phillips on the [Feb. 



circumstance in his Manual of Chemistry, nor does Dr. Thomson 

 or Dr. Henry attempt to explain the fact in their respective 

 works, although they have given the results of Mr. Dalton's 

 experiments. Dr. Murray, in the last edition of his System of 

 Chemistry, observes, "^^ this circumstance is extremely singular ; 

 augmented solubility from cold is contrary to all analogy, as well 

 as to the principle on which the relation of temperature to solu- 

 tion depends." 



With the intention of determining the comparative solubility 

 of lime in water of different temperatures, and if possible also to 

 discover the cause of the difference, I prepared some lime- 

 water at the temperature of the atmosphere, which was then about 

 60° of Fahrenheit. A wine pint which had been filtered with as 

 little exposure to the atmosphere as possible was decomposed 

 by adding solution of carbonate of ammonia. The solution was 

 examined with oxalic acid, and it appeared that the whole of the 

 lime was precipitated by the carbonic acid of the carbonate of 

 ammonia. The precipitated carbonate of lime being washed 

 and dried weighed 17*3 grs. equivalent, according to Dr. Wol- 

 laston, to 9'7 grs. of hme ; and as a pint of Hme-water weighs 

 about 7300 grs. it follows that water at 60° dissolves about -.^ 

 of its weight, agreeing pretty nearly with Mr. Dalton^s state- 

 ment, and still more so with Dr. Thomson's, who finds that 

 " 758 grs. of cold water dissolve one of lime." 



I next boiled some hydrate of lime in water, and filtered it 

 with as little exposure to the air, and as rapidly as possible. A 

 pint of this decomposed, as in the former case, by carbonate of 

 ammonia, gave 10*5 grs. of carbonate of lime, equal, according to 

 the scale, to 5*9 grs. of lime. Boihng water, therefore, as appears 

 by this, dissolves only -nrW ^^ ^^^ weight of hme. I repeated 

 this experiment, taking exactly 10,000 grs. of the lime water, 

 the carbonate of hme weighed 14 grs. = 7*8 of Hme ; so that 

 the hot water had taken up -^Vo ^^ *ts weight, agreeing very 

 closely with the former experiment, and as nearly with Mr. Dal- 

 ton'sas 1280 to 1270. 



Some lime water was now prepared by putting hydrate into 

 water, a very little above the temperature of 32 . This being 

 filtered with the usual precaution, 10,000 grs. were decomposed 

 in the manner already stated, and 27 grs. of carbonate of hme 

 were obtained, confirming very nearly Mr. Dalton's opinion that 

 water at 32° would dissolve twice as much hme as water at 212**: 

 27 grs. of carbonate of lime are equivalent to 15*2 of lime, and 

 consequently water at near 32° dissolves -^^ of its weight of 

 lime : to be exactly double, it should be ■^^, 



Having, by these experiments, satisfied myself of the correct- 

 ness of the facts stated by Mr. Dalton, I proceeded to inquire 

 into their cause. With this intention, I prepared some lime 

 water at a little above 32° of Fahrenheit, and heated to ebullition 

 46 ottnces in a flask, from which a long tube issued to prevent 



