( V ) 



« not attained to a degree of proficiency to obferve fuch objeifts triuv. 

 ' For my own part, I will not fcruple to ailert, that I can clearly 

 ' place before my eye the fmallelt fpecies of thofe animalcules con- 

 ' cerning which I now write, and can as plainly fee them endued 

 ' with life, as with the naked eye we behold fmall flies, or gnats 

 ' fporting in the open air, though thefe animalcules are more than a 

 ' inillion of degrees lets than a large grain of fand. For I not only 

 ' behold their motions in all diredlions, but I alfo iee them turn 

 ' about, remain ftill, and Ibmetimes expire ; and the lai-ger kinds of 

 ' them I as plainly perceive running along, as we do mice with the 

 ' naked eye. Nay, 1 fee fome of them open their mouths, and move 

 ' the organs or parts within them ; and I have difcovered hairs at 

 ' the mouths of fome of thefe fpecies, though they were fome thou- 



* fand degrees lefs than a grain of fand. 



' But fuicc it is pronounced to be incredible, that within the fpace 



* occupied by a grain of fand fo many animalcules can be contained, 

 ' and that it is impoflible for me to calculate truly fuch numbers, I 

 ' liavc thought on the following method of computation, to place. 

 ' this matter in a clearer liglit. I lay it down as a pofition or truth, 

 ' that with the microfcope I can fee the fpace occupied by a grain of 

 'fand* magnified to the fize reprefented by the circle A BGC. 

 ' Next, I Ilippofe that I obferve within this fpace an animalcule 



* fwimming or running along, and appearing of the fize reprefented 

 ' at D. Taking the meafure of this by my eye, I conceive the axis 

 ' or thicknefs of the animalcule thus piclured at D, to be the twelfth 

 ' part of the axis of the grain of fand reprefented by ABGC ; there- 

 ' fore, by the common rules of arithmetic, the folid contents of a 



* fphere or globe whofe circumference is defcribcd by the circle 

 'ABGC, will be 1728 times larger than a fphere of the fize of D. 



* ' A grain of (;inJ ihe Author i;i anathiT place acfcribes to be of that fj.-t calLJ fcowering, 



* fanJj or glafs-grinJers fand. 



ujl library'* 



vf 



