M 148- i c r o s c o p i c a l E s s a y s .
examine the particles diflincl from each other; ex. gr. take a
final! quantity o f the ferum o f the human blood, and lhake a
piece of craflamentum 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 glafi;
An apparatus has been defcribed by feveral authors for viewing
the circulation o f the blood in the mefentery of a frog; by
this inftrument curiofity may be gratified; but it is at the expence
o f humanity, and that without any probability o f extending the
bounds o f fcience, or promoting the good o f mankind. N o
rational excufe can be given for depriving a poor creature of it’s,
life, the greateft boon that nature can bellow, or even'to put it
in pain, but an objeft o f utility; he who does from hence procure
benefits for the higher orders o f animated beings, may be permitted
to exert the power which he poffefles 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 o f an inordinate
fancy.
« ---------------- God, when he charg’d the Jew
T ’ alfift his foe’s down-fallen beaft to rife;
And when the bulh-exploring boy, that feiz’d
The young, to let the parent bird go free,
Prov’d
Prov’d he not plainly that his meaner works
Are yet his care, and have an intreft all 1
A ll in the univerfal Father’s love?”
* * * * * * * * * *
«■ I would not enter on, my lift o f friends
(Tho’ grac’d with polifh’d manners and fine fenfe,
Y e t wanting fenfibility) the man
Who needlefsly lets foot upon a worm.
An inadvertent ftep< may crulh the fnail
That crawls at ev’ning in the public path;
But he that has humanity, forewarn d,
W ill tread afide, andletthe reptile live.
* * * * * * * * * *
* * * * * * * * * *
“ A neceffary aft incurs no blame:
Not fo when held within their proper bounds,
And guiltlefs of offence, they range the air,
Or take their paftime in the fpacious field:
There they are privileg’d. And he that hunts,
Or harms them there, is guilty of a wrong.
Cowper’s Poems, vol. 2, b, vi,