[ 198 J 



CHAP. XI. 



'A Microfcopical Difcovery. 



HAVING lately had the Pleafure of 

 Ihewing, Sir, to You and feveral other 

 curious Gentlemen a Difcovery made by the 

 Microfcope, which both You and They have 

 judged worthy Notice j I hope it will not be 

 thought improper to add it to thefe Expe- 

 riments, 



Keeping a fmall Quantity of the black 

 Mud of the Thames with fome Worms 

 therein to feed my Polype 5^ in an ear then Veffel 

 that contains cbout half a Pint 3 I poured 

 every Day a little Water thereon, to fupply 

 the Worms with frefli Nourilhment and 

 prevent their becoming putrid. This Wa- 

 ter, however, I conftantly drained off in a 

 few Minirtes, leaving none of it in the Vef- 

 fel but what the Mud ibaked in ; fo that it 

 appeared always moift, but never wet. 



In fome Mud that had been thus treated 

 for about a Fortnight, I obferved in many 

 Places, and particularly about its Edges, on 

 the fixteenth of laft September^ a great many 

 glittering or Ihining minute Bodies, in Ap- 

 pearance and Size not much unlike fome of 

 the clear tranfparent Grains of large Sea- 

 Sand^ which indeed at firft I imagined them 



to 



