248 



Microscopical Essays, 



examine the particles diftincl from each other ; ex. gr, take a 

 fmall quantity of the ferum of the human blood, and (hake a 

 piece of craffamentum in it, till it is coloured a little with the red 

 particles ; then with a foft hair pencil fpread a little of it on a 

 piece of thin glafs, and place this glafs under the microfcope, in 

 fuch a manner as not to be quite horizontal, but rather higher at' 

 one end than the other ; by which means, the ferum will flow 

 from the higher to the lower extremity, and as it flows fome of 

 the particles will be found to fwim on their flat fides, and will 

 appear to have a dark fpot in the middle : others will turn over 

 from one fide to the other, as they roll down the glafs* 



An apparatus has been defcribed by feveral authors for view- 

 ing the circulation of the blood in the mefentery of a frog ; by 

 this mftrument curiofity may be gratified ; but it is at the expenee 

 of humanity, and that without any probability of extending the 

 bounds of fcience, or promoting the good of mankind. No- 

 rational exeufe can be given for depriving a poor creature of it's 

 life, the greatefl boon that nature can bellow, or even to put it 

 in pain, but an object of utility.; he who does from hence procure 

 benefits for the higher orders of animated beings, may be per- 

 mitted to exert the power which he poiTelfes over the inferior 

 orders of life. But he greatly errs, if he thinks thefe powers may 

 be ufed to gratify wanton curiofity, or the fports of an in- 

 ordinate fancy. 



« , God, when he charg'd the Jew 



T' affift his foe's down-fallen beaft to rife ; 

 And when the bulb-exploring boy, that feiz'd 

 The young, to let the parent bird go free, 



Prov'i 



