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to the same axis. Round the circumference of the latter, which was eleven 
inches in diameter, numerous seeds of the garden bean, which had been 
soaked in water to produce their greatest degree of expansion, were bound, 
at short distances from each other. The radicles of these seeds were made 
to point in every direction ; some towards the centre of the wheel, and others 
in the opposite direction; others as tangents to its curve, some pointing back¬ 
wards, and others forwards, relative to its motion; and others pointing in 
opposite directions in lines parallel with the axis of the wheels. The whole 
was inclosed in a box, and secured by a lock, and a wire grate was placed 
to prevent the ingress of any body capable of impeding the motion of the 
wheels. 
The water being then admitted, the wheels performed something more 
than 150 revolutions in a minute; and the position of the seeds relative to 
the earth was of course as often perfectly inverted, within the same period 
of time; by which I conceive that the influence of gravitation must have 
been wholly suspended. 
In a few days the seeds began to germinate, and as the truth of some of 
the opinions I had communicated to you, and of many others which I had 
long entertained, depended on the result of the experiment, I watched its 
progress with some anxiety, though not with much apprehension; and I had 
soon the pleasure to see that the radicles, in whatever direction they were 
protruded from the position of the seed, turned their points outwards from 
the circumference of the wheel, and in their subsequent growth receded 
nearly at right angles from its axis. The plumes, on the contrary, took 
the opposite direction, and in a few days their points all met in the centre 
of the wheel. Three of these plants were suffered to remain on the wheel, 
and were secured to its spokes to prevent their being shaken off by its mo¬ 
tion. The stems of these plants soon extended beyond the centre of the 
wheel: but the same cause, which first occasioned them to approach its axis, 
still operating, their points returned and met again at its centre. 
The motion of the wheel being in this experiment vertical, the radicle 
and plume of every seed occupied, during a minute portion of time in each 
revolution, precisely the same position they would have assumed had the 
seeds vegetated at rest; and as gravitation and centrifugal force also acted 
in lines parallel with the vertical motion and surface of the wheel, I con¬ 
ceived that some slight objections might be urged against the conclusions I 
felt inclined to draw. I therefore added to the machinery I have described 
3 I 
