222 



SCIENTIFIC NEWS. 



ten ounces of highly concentrated fulphuric acid. After each 

 introduction of acid, clofe the tubulure carefully, and put in 

 no more frelh acid till the fait has quite ceafed bubbling. 

 The cork of the other neck of the bottle muft be taken out 

 from time to time, to fuffer the air condenfed above the al- 

 cohol to efcape. 



After all the acid is introduced, place the retort on a fand- 

 bath, and heat it gradually till all the muriatic acid be ex- 

 pelled. During this part of the operation, care muft be taken 

 frequently to cool the bottle containing the alcohol, by wrap- 

 ping a wet cloth round it. 



The alcohol, thus charged with acid, is then put into a re- 

 tort and diftilled to one half. Shake the diftilled liquor with 

 a fufficient quantity of alcaline ley to carry off the acid, de- 

 cant the fupernatant portion, which is ether, and keep it in 

 bottles well corked. From the above mentioned quantities, 

 two ounces and a half of ether are ufually obtained. 



M. Bofla aflerts, that by operating with thermoxy dated 

 muriatic acid, light alcoholic ether can never be obtained, 

 but only a heavy oleaginous ether, which, inftead of floating 

 on water, falls to the bottom of that liquid. 



On the Effecls produced by the Decortication of Trees. 



Decortication SEVERAL papers have lately appeared in the American 



Philofophical Tranfa&ions, and other fcientific works, re- 

 commending the depriving trees of their bark as a means of 

 exterminating noxious infects which find fhelter in the crevices 

 of the bark, and between it and the body of the tree. From 

 the effects produced on two apple-trees, as related in the 

 Monthly Magazine for laft month, though the fource from 

 which their information is derived does not appear, it would 

 feem that this practice is deftructive of the tree itfelf. The 

 relator aflerts, that, one of the trees died in May following 

 the operation, and the other before the neighbouring trees 

 had ihed their leaves. He alfo ftates that the denuded trees 

 were affected by feveral long fiflures, which he attributes to 

 the alterations of heat and cold, and confiders as the im- 

 mediate caufe of their death. He concludes by a query, 



whether 





