Radicle and Germen of Seeds. 125 



of the wheel, I conceived that some slight objections might 

 be urged against the conclusions I felt inclined to draw. I 

 therefore added to the machinery I have described another 

 wheel, which moved horizontally over the vertical wheels ; 

 and to this, by means of multiplying wheels of different 

 powers, I was enabled to give many different degrees of ve- 

 locity. Round the circumference of the horizontal wheel, 

 whose diameter was also eleven inches, seeds of the bean 

 were bound as in the experiment which I have already de- 

 scribed, and it was then made to perform 250 revolutions 

 in a minute. By the rapid motion of the water-wheel much 

 water was thrown upwards on the horizontal wheel, part of 

 which supplied the seeds upon it with moisture, and the re- 

 mainder was dispersed, in a light and constant shower, over 

 the seeds in the vertical wheel, and on others placed to vege- 

 tate at rest in different parts of the box. 



Every seed on the horizontal wheel, though moving with 

 great rapidity, necessarily retained the same position relative 

 to the attraction of the earth ; and therefore the operation of 

 gravitation could not be suspended, though it might be coun- 

 teracted, in a very considerable degree, by centrifugal force ; 

 and the difference I had anticipated between the effects of 

 rapid vertical and horizontal motion soon became sufficiently 

 obvious. The radicles pointed downwards about ten de- 

 grees below, and the germens as many degrees above, the 

 horizontal line of the wheel's motion; centrifugal force hav- 

 ing made both to deviate 80 degrees from the perpendicular 

 direction each would have taken, had it vegetated at rest. 

 Gradually diminishing the rapidity of the motion of the ho- 

 rizontal wheel, the radicles descended more perpendicularly, 

 and the germens grew more upright; and when it did not 

 perform more than 80 revolutions in a minute, the radicle 

 pointed out about 45 degrees below, and the germen as much 

 above, the horizontal line, the one always receding from, 

 and the other approaching to, the axis of the wheel. 



I would not, however, be understood to assert, that the ve- 

 locity of 250 or SO horizontal revolutions in a minute will al- 

 ways give accurately the degrees of depression and elevation of 

 the radicle and germen which I have mentioned; for the rapi- 

 dity 



