VOL. LVII.] PHILOSOPHICAL TRANSACTIONS. 489 



(a) Four ounces of the spirit of salt of the 2d experiment, was perfectly 

 saturated with 4 oz. of whiting. (b) Four ounces of the spirit of salt of 

 the 3d experiment, was perfectly saturated with 4 oz. of ditto, (c) As much 

 water as contained 4 oz. of vapour of the 2d experiment, was saturated with 

 5 oz. of ditto, (d) As much water as contained 4 oz. of vapour of the 3d 

 experiment, was saturated with 6 oz. of ditto. The reason of using more 

 whiting with some than with others, was on account of the different strength 

 of the acids ; and as there was a greater quantity of whiting than necessary used 

 in these experiments, to saturate the acids, the undissolved part must consist of 

 whiting; and if any acid of vitriol in the acids, of whiting and selenite. In 

 order to separate the selenite from the whiting, a large portion of distilled 

 vinegar was made use of, which dissolves the whiting, it being a calcarious 

 earth; and in order to promote the solution, heat was made use of 



The undissolved pari of (a) being perfectly saturated with a sufficient quantity 

 of distilled vinegar, and afterwards repeatedly washed with pure water, and <lried, 

 weighed -1- oz. and 26 gr. — (b) treated as (a) weighed -^oz. and 52 gr. — (c) 

 treated as (a) weighed 3g gr. — (d) treated as (a) weighed 42 gr. — * One ounce 

 of whiting treated as (a) left 7 gr. 



From these experiments it appears, that the 4 ounces of acid marked (a) con- 

 tain as much acid of vitriol as will make 4 an oz. less 2 gr. of selenite. — 4 oz. of acid 

 marked (b) 4 anoz. and 24 grs. of ditto. — 4 oz. of the acid vapour marked (c) 

 4 gr. of ditto. — 4 oz. of the acid vapour marked (d) none. — Hence it is evident, 

 that the vapour of the acid of salt condensed in water, when distilled slowly, 

 contains no acid of vitriol; and that even when it is distilled quick, it contains 

 so small a quantity as is not worth notice. 



If 10 oz. of sea salt are distilled in the common manner, with an equal 

 quantity of oil of vitriol unmixed with water, there only distil 2 oz. of spirit 

 of salt; whereas, if distilled in this new manner, we not only obtain the like 

 quantity, but likewise 4 oz. and -l more, which are condensed in the water; 

 so that in making this concentrated spirit of sea salt, there is a saving of above 

 double the quantity, which would be lost in the common method of operating. 



Of the heat produced by the vapours of spirit of salt passing through water, 

 spirit of wine, and oil of turpentine. — ^Three quarts of water were put into 

 a gallon stone bottle, and made use of to condense the vapours, as in experiment 

 the 2d, fig. F ; in 3 hours and a half after the fire was made under the retort, 

 the water in the stone bottle had acquired the degree of 212, which is the 

 mark of boiling water in Fahrenheit's thermometer; and at this time there was 



• As whiting contains lome parts which are not soluble in distilled rinegar, it was necessary 

 to know how much of this an ounce contained, which must be deducted in proportion to the 

 quantity used for the experiments, a, b, c, and d. — Orig. 



VOL. XII. 3 R 'I" I'" 



