A defaipt'wn of fame fpecies of mhiiitc Infects, found in frefli 

 water, in a Letter to Signer Anthonio Mag/iabccM,* at Florence. 



To the illustrious, learned, and famous Signor Anthonio 



Magiiabechi. 



XHE very obliging letter with which you have honoured me, (to 

 which- were added what has lately been publiflied in Italy by the 

 learned, containing the ciu'ious invention of incloling gunpowder in 

 a bag, and computing the force which fuch bag would rellli before 

 it burll) is come to my hands ; and I beg you to be aflured that it 

 was moft acceptable to me : and for the favour of your letter, as 

 well as the communication therein contained, I defire to return you 

 my grateful thanks. 



In reliance on your accuftomed friendlhip, I have been induced 

 to impart to you my obfervations and reflexions rei'peding fome 

 very minute animalcules, hitherto very little noticed, which are found 

 in the waters of this countrv. 



Being employed in fearching after certain animalcules, which I 

 expelled to find in thofe ditches or canals which divide our fields, 

 I faw various fpecies of creatures, but none of thofe which I was 

 then in fearch of. Amonsc thefe I obferved certain animalcules, 

 Avithin whofe bodies I law fo quick a motion as to exceed belief; 

 they were about the fize of a large grain of fimd, and their bodies 

 being tranfparent, that internal motion could plainly be feen< 

 Among other things, I faw in the body of one of thefe anhnalcules 

 a bright and round corpufcle, placed near the head, and inwliicha 

 very wonderful fwift motion w^as to be feen, confifting of an alter- 

 nate extenfion and contradion. This particle I concluded to be the 



* Magiiabechi was at (his time Librarian to tlie Grand Duke of Tuscany : hc was not lefs 

 famous for his learning than his peculiarities, of which foTeral anecdotes arc related in tha 

 AdvcDturcr, 



