INDEX. 



7*9 



P 



Polypes, directions for finding, &c. 152; defcribed, 393; re- 

 production of, 418. 

 Puceron, fee aphis. 



Probofcis of a bee defcribed, 362 ; of the tabanus, 704. 

 Pith confidered, 671. 



R 



Rays of light, experiments made with, 29 5 continued, 35, 37, 

 Refraction, experiments on, 35, 36. 

 Rind of trees confidered, p. 654. 



S 



Smith, Dr. his improvement on the compound microfcope, 18. 

 Solar microfcope defcribed, 19; improvements on do. 22; fully 



defcribed, 99; improved fo as to viewopake as well as tranfpa- 



rent objects, 92^; how to ufe it, 95. 

 Swammerdam, his mode of preparing objects^ 134, 138. 

 Salts, how prepared, 163. 



Silk worm, it's changes and manner offpinning, 211. 



Skin of the lump fifh, 388 ; of the foal, 392. 



Scales of fifh, 391 • of the parrot fifh, 392 ; fea perch, 392. 



Haddock, 392 ; a perch from the Weft Indies, 392 ; foal, 392, 



Spider confidered, 700. 



Seeds confidered, 692. 



T 



Torre, T. Di. of Naples, his mode of making and ufmg glafs 

 globules, 10, 



6 Termites 



