&c. . 89 



from the beginninff of last June to the end of September. _ 



rv • t • . , Experiments, 



JJunng this time, the sand-bath had very seldom been &c. on an arti- 



heated, but the vessel was occasionally shaken. ficlal substance 



At the end of the period above mentioned, six ounces ^.^Jj^g ^jfj^^I 

 of boiling water were added, and the whole being poured ing matter, 

 upon a fdter, was repeatedly washed, and was afterwards 

 dried on a sand-bath in a heat not much exceeding SOQo. 



The sawdust appeared to be reduced to a granulated 

 coal, partly pulverulent, and partly clotted; the whole 

 weighed 210 grains. 



One hundred and five grains of this coal were put into 

 a platina crucible, and were exposed to a red heat under 

 a muffle. At the same time, an equal quantity of char- 

 coal made from the same oak sawdust, was placed in 

 another vessel by the side of the former. 



The charcoal was speedily consumed, and left some 

 brownish-white ashes, which as usual, afforded alkali, 

 with a trace of a sulphate, which was probably sulphate 

 of potash. 



On the contrary, the coal formed by the humid way, 

 burned without flame, similar to the Kilkenny coal, and 

 others which do not contain bitumen. It was very slowly 

 consumed, like the mineral coals above mentioned, and ' 

 left some pale red ashes, which weighed 2 grains. These 

 Hiihcs did not 2/ield the smallest vestige of alkali, and the 

 only saline substance which could be obtained, was a 

 very small portion of sulphate of potash, which did not 

 amount to more than one-tifth of a grain ; and it is pro- 

 bable, that had the coal been more copiously washed, 

 even this small portion of the neutral salt would not have 

 been obtained. ' 



2. 



At the time when the preceding experiment was began, 

 T also put 480 grains of the oak sawdust into another 

 matrass, and having added four ounces of common muri- 

 atic acid, the whole was suffered to remain during the 

 period which has been mentioned. 



At the end of the four months, the remainder of the 

 acid was for the greater part driven off by heat not ex- 

 ceeding 300°. The sawdust then had the appearance of 

 a brownish-black mass, on which about a pint of boiling 



Vol. XV.— Oct. 1806, N distilled 



