240 wit. Harrison's botanical pres^. 



Remarks on the It may bc neceflary to explain fome parts of the (Iru6!ure 



vantaaes'of this °^ ^^^ prefs. The holes in the bottomeft and uppermoft boxes 



contrivance, are to admit of the circulation of air and the evaporation of 



moifture, which will be confiderable when the prefs without 



its cap is placed within the influence of the fun or fire, as it 



always ought to be : and the fmall triangular pieces of wood 



in the corners of each box, are to prevent the upper boxes 



from preffing folely on the canvas bottom of the loweft 



box, when any number are lifted together : thefe may at 



firft fight appear likely to impede the prefllire of the fand 



when placed in the prefs, but this objeflion will vanifti when 



it is recollected that each box contains an inch depth of 



fand : and it is evident, on examination of the prefs, that 



the fides of the boxes ferve no other purpofe than to keep 



the fand together ; for they are perceptibly moveable in a 



perpendicular direftion, and fuftain no prefliire from the 



fuperior boxes ; therefore the plant is placed as if in a heap 



of fand. 



The beft me* I am afraid I have already trefpalTed too long on the atten- 



thod of prefcrv- ^j^^^ ^j- ^j^^ reader, but I cannot difmifs the fubjea without 



wg dried plants _ ' , -' 



is to ftitch ihem offering a few obfervations on the manner of preferving plants 

 to a paper. after they are dried. There have been at lead three methods 



nfed: firfi, fixing them to paper by the aid of gum-water: 

 fecond, placing them loofely in a book : third, flitching them 

 with thread to a (beet of paper. The fir ft plan appears to me 

 the lead eligible, for it cannot be neatly executed unlefs the 

 plant be prefied nearly flat, and by fixing it to the paper it 

 can never admit of an accurate examination in future, but 

 becomes a mere pI6lure, and a very iraperfeft one; for almoft 

 every diftinguiQiing character, efpecially the parts of fru<5tifi- 

 cation, are injured or defaced ; even the general habit is often 

 fo much altered tliat the plant could not be afcertained, were 

 it not for the name generally fubfcribed at its root. The 

 fecond plan is alfo objedionable; for though the plant may 

 at any time be fubjeded to examination, yet by lying loofe in 

 a book, it is very apt to be broken by the leafl motion, par- 

 ticularly when kept dry, which all preferved plants ought to 

 be. The third appears to me the leaft liable to objection ; 

 for if the plant be neatly Hitched down, it will not be fubjeft 

 to fuch motion as to injure its parts; and by cutting the 



thread* 



