Botany. — A new volcanic JJland. ffl. 



The pnifliat of potafli gives a blue colour to the writing, 

 whether that effaced, or that which has been fubftituted for 

 it ; which is fufficient to detecl fraud of this kind : it gives. to 

 the paper, at the fame time, a (light tint of blue. To employ 

 it, you put into a bafon, or any other deep vefl'el, and of a 

 fuitable fize, as much water as may be fufficient for im- 

 iiierfing the leaves of paper which you wifh to fubjeil to ex- 

 amination. You then add about half a thimble-full of the 

 pruffiat ; and, when it has been well mixed with the water, 

 you immerfe in the liquid a leaf of paper. When it has im- 

 bibed the liquid well, a few drops of fulphuric or any other 

 acid, poured into the mixture in fuch a manner as to render 

 it flightly acid, will be fufficient to make the writing re- 

 appear. It is well known that the fame fubftance poffiflTes 

 the property of reviving old writing if employed in the like 

 manner. 



BOTANY. 



On fome mountains in South Pruflia a plant was difco- 

 vered in autumn laft which yields a fine beautiful filk. It 

 grows on dry mountains, covered with bufhes, to a height of 

 three or four feet; has roots of the (hape of quitch-grafs; 

 heart (liaped leaves, of a light-green colour; a foft ftalk, of 

 the thicknefs of a quill, covered with a firm filky baft; and 

 a fruit fimdar to that of the filk-plant of Syria, with the dif- 

 f(.rence only, that the pods which contain the feed and filk- 

 wool are more pointed and fmaller. The fiik cannot be dif- 

 tinguilLed from that of Syria, 



A NEW VOLCANIC ISLAND. 



A letter from the celebrated naturalift Pallas, dated the 

 Tauride, announces, that on the 5th of September lalt an 

 ifland fuddenly made its appearance in the fea of Azof, at 

 the diftance of 150 toifes from the {l:jore. This phenomenon 

 was preceded by a noife like that of thunder, and accompa- 

 nied with an eruption of fmoke and flames, the explofiou of 

 which was as loud as that of a large piece of ordnance : at 

 the fame time a violent fhock of an earthquake was experi- 

 enced from Cuban as far as Catrinodan. 



N a VACCINE 



