264 ES8AY XXIV. 



be done in consequence of the laws of double attractions. 

 Let the salve be sliced and rubbed in a glass mortar, with a 

 mixture consisting of eight parts of strong spirit of wine 

 and one part of oil of vitriol. This white mixture is to be 

 poured on a filter, and water is to be added to the liquor 

 that runs through, upon which the oil that was contained in 

 the salve will be separated. I wished to recompose salve by 

 boiling this oil again with litharge, but it grew thick before 

 it could be made to boil. From the water, which I took 

 care to decant, I obtained some of the sweet matter so often 

 mentioned, though indeed but in very small quantity. 



* 



LETTER FROM MR. SCHEELE TO DR. CRELL. 1 



It seems as if the opinion maintained by many chemists 

 and philosophers, that fixed air is a combination of pure or 

 dephlogisticated air, with a certain portion of phlogiston, is 

 not yet so completely proved. Many rather suppose that 

 the pure air must be further dephlogisticated, in order to 

 become aerial acid ; and that, when it is totally free from 

 phlogiston, it constitutes nitrous acid. Pure air, fit for 

 supporting of combustion, is a kind of sulphur, consisting of 

 phlogiston and the matter of heat. 



In my Essay upon Ether, I have related a great number 

 of experiments made with manganese, spirit of wine, and 

 acids. I have at the same time shown that acetous ether 

 is never generated without the assistance of muriatic or 

 nitrous acid. 



In your New Discoveries (Part 8, p. Ill), there is an 

 observation on my method of preparing the flowers of 



litharge, which are boiled over a slow fire, with continual agitation and 

 the addition of a little boiling water now and then, till they combine. 

 Pharm. tiuec., 1779, p. 74. T. 



1 Ckemische Annalen, Th. viii. S. 123. 



