124 On the Direction of the 



each other. The radicles of these seeds were made to point 

 an every direction ; some towards the centre of the wheel, 

 and others in the opposite direction ; others as tangents to 

 its curve, some pointing backwards, and others forwards, 

 relative to its motion ; and others pointing in opposite di- 

 rections 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 ca- 

 pable 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 germens, 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 motion. 

 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 re- 

 turned and met again at its centre. 



The motion of the wheel being in this experiment ver- 

 tical, the radical and germen of every seed occupied, during 

 a minute portion of time in each revolution, precisely the 

 same position they would have assumed, had the seeds vege- 

 tated at rest; and as gravitation and centrifugal force also 

 acted in lines parallel with the vertical motion and surface 



of 



