VOL. XLVm,] PHILOSOPHICAL TRANSACTIONS. ' 327 



haven, or open harbour. The mount, from its Cornish name,* we must con- 

 clude to have stood formerly in a wood, but now at full tide is half a mile in the 

 sea, and not a tree near it. 



Fill. Of Mr. Applehxfs Process to make Sea water Fresh. By W. Watson, 



F.R.S. p. 69. 



Mr. Appleby's process is as follows : Into 20 gallons of sea water put 6 oz. 

 of a fixed alkali, prepared with quick-lime as strong as lapis infernalis, and 6 oz. 

 of bones calcined to whiteness, and finely powdered. With a slow fire, draw 

 off in a common still 15 gallons. — Mr. Appleby conceives, that the alkali here 

 employed, is the best adapted to prevent the bituminous matter in sea water from 

 rising by the heat in distillation. 



The experiments of Mr. Clark, chemical operator at Apothecaries' hall. — Into 

 •a spoonful of the distilled sea-water he put 20 drops of a solution of silver in 

 aquafortis: he likewise did the same with the like quantity of common water 

 distilled. There appeared no change in either, and both retained their transpa- 

 rency. This demonstrates, that the distilled sea-water is by the process entirely 

 freed from marine salt, or its acid spirit. For, if we take a spoonful of common 

 distilled water, and add the least particle of sea-salt, with the point of a pen- 

 knife, and then drop into the mixture 1 or 2 drops of the solution of silver, it 

 will appear turbid and milky. 



From the number of animal bodies constantly perishing in the sea, it may 

 reasonably be suspected, that a volatile urinous spirit may be retained in this dis- 

 tilled water; and this is evident from the following experiment: into a spoonful 

 of distilled sea-water drop 10 drops of a strong solution of sugar of lead, and 

 the mixture immediately becomes turbid and milky. Into another spoonful of 

 common distilled water, with 2 drops of spirit of sal ammoniac, and 10 drops of 

 a solution of sugar of lead ; and this mixture had the same appearance with the 

 foregoing. 



If into a spoonful of common distilled water be dropped 1 drop of oil of tartar 

 per deliquium, and then added 10 drops of a strong solution of corrosive subli- 

 mate, the mixture will immediately become turbid and brown, and with a few 

 drops of the solution of silver, it will be precipitated, and turn milky. It is 

 therefore a volatile alkali, and not a fixed one, that is contained in this water. 



The solution of silver will not discover a volatile alkali contained in water, but 

 very plainly a fixed one. A solution of sugar of lead will not discover a small 

 quantity of marine salt or spirit, till we add more. A solution of sublimate will 

 manifest both a volatile and fixed alkali. 



• Guavas lake, signifying the grey rock in a wootl— Orig. 



