I AKIMALCULA OF mPUSIONS. ^OJ 



nous, that light or heat may traverfe them with- 

 out impreflion. Even the denfeft and moO: 

 opaque fubftances become tranJTparent when di- 

 vided into lamina extremely thin. Gold is a moil 

 remarkable inflance ( i ). May not the germs of 

 animalcula of the lowed clafs be among thofe 

 fubllances fo thin and tranfparent that heat may 

 traverfe them withoiit alteration ? Let this idea 

 be profecuted farther : it merits confideration. 



The animal and vegetable kingdom firfl appear 

 under the form of a whitilh jelly more or lef& 

 tranfparent. Such is the original form of the 

 majeftic oak and the powerful rhinoceros : in the 

 beginning they are but a drop of jelly, and llill 

 lefs. Were we permitted to afcend higher in the 

 animal and vegetable origin, we ffiould find them 

 much more tranfparent. We are acquainted 



with. 



(i) So far as I know, it can only bcrfald that gold 

 Is not abfolutely opaque ; for brought to the greateft 

 degree of thinnefs, ttu^s-^ part of an inch, it appears of 

 a green colour. Poffibly other metals might tranfmit light 

 if they were fufficiently malleable to bring their pores in- 

 to a ftraight line ; for it is hardly to be fuppofed that any 

 fubftance is without pores, or does not confift of compO' 

 nent parts, until we arrive at the atoms of matter, if there 

 is fuch a thing. But it is a very different queilion whether 

 the pores of fome fubftances may not be fmaller than the 

 particles of light, however minute ihefe are fuppofsd to 



