i$o Mr. Bent/jam's Patent Method. 



us, that "air is either known to be, or iufpecled of being, an, 

 obftacle to art and manufacture, in a greaj variety of ways ;" 

 but it would be inful ting, our readers to enumerate thofe he 



points out, as they niuft be as well acquainted with them as 

 Mr. Bentham bimfelf. We mall only obferve in pairing, 

 that, a.s he admits the fa£t to have been known before, it ap- 

 pears odd that he fhould call the idea his invention. 



He then proceeds to exemplify the nils that may be 

 made of his invention, in preferving fubftanc.es animal and 

 able from putrefaction. It was known, before Mr. 

 Bentham was born, that fuch fubftances misrht in fome de- 

 gree be preferved for a long time in vacuo : but perhaps 

 Mr. Bentham has found out fome new way of producing a 

 vacuum, and therefore is entitled to the exclusive ufe of that 

 method? — No ! lie fays the air mutt he extracted from the 

 yeffel or chamber by " an air-pump, or otherwife j" but the 

 other ways he has kept to himfelf. Mr. Bentham fuppofes, 

 that, in the practice of potting folic! fubftances^ the fat, which 

 in a melted flate is thrown round them, acts " in good 

 mcufu.v" by excluding the air. It is partly true; but it. 

 performs another work which his vacuum would entirely 

 deftroy — it prevents the efcape of the juices. 



" Many of the changes,'' fays the patentee, " to which 



bodies are fubje& in point of colour, are known to refult 



from the action of the air. An exhaufted chamber affords 



the means of preferving them from all fuch changes, for any 



th of time/'' This, was known- long ago j but we fhalj 



i: one uf( to which thofe may apply it, who fliall firft 



ion horn the patentee. Such as with to 



preferve the of their clothes from being injured by 



th . t< ,, of the air, may get an air tight-cafe made for 



thehafelves to walk in — ihc bottom part terminating in a 



■f boots. After fthey have inclofed themfelves, let their 



fervant, " by an air-pump or otherwife." extract the air, 



"care being taken at the fame time to exclude the light, 



,- i of that elen tt alfo is found to influence 



the 



