318 



The plant does 

 not run except 

 along wood. 



SCIENTIFIC NEWS. 



This plant has no adhefive powers, bat in conta6t with 

 wood. If it could pafs over brick or mortar, it might be 

 feen to fpring from the cellars, and infeft half the houfes in 

 the kingdom. 



In fhort, the wainfcot is to be kept free from conhi6t with 

 the joifts and floor ; and I believe it cannot be better efFeded 

 than I have defer ibed. 



I am, SIR, 



Your obedient Servant, 

 Z>fc. 21, 1799. BENJAMIN JOHNSON. 



To the Secretary. 



(To he continued.) 



SCIENTIFIC NEWS, 



What are the 

 nature of 

 tnarles, their 

 fpecies. and the 

 beft modes of 

 ufing'thena ? 



Their external 

 charafters ne- 

 ceffary to be 

 known. 



Sheep liable to 

 the vertigo or 

 dunt. 



In France, 

 900,000, or 

 950,000, that 

 is 3 or 4. in 100 

 die of it yearly. 



Society of Agriculture, Commerce, and Arts, at Boulogne-fur- 

 Mer* 



JL HE following queftions propofed by this fociety are noticed 

 as of general and not local import. 



1. It is generally acknowledged, that marling is one of the 

 moft important means of improving land ; accordingly the fo- 

 ciety will beftow a prize on the memoir, in which the nature 

 of marles, their various fpecies, and the moft advantageous 

 mode of ufingthera, according to the difference of foils, fliail 

 be beft unfolded. 



The author will be particularly careful to point out to farmers 

 external charaders, that will enable them eafily to diftinguifti 

 each fpecies &i marie. 



2. Sheep are fuhjed to a diforder known by the name of 

 vertigo, or the dunt. The number that die of this diforder 

 may be eftimated without exaggeration, at three or four in a 

 hundred annually. If then there J^e about thirty millions in 

 France, we may reckon, that nine hundred, or nine imndred 

 and fifty thoufand are thus loft eyery year. It is occafioned 

 by a hydatid formed in the head of the flieep. This hydatid 



* Magaztn EncyclopeMque, No. 3. June, 1803. p. 401* 



contains 



