584 



FARMERS' REGISTER 



[No. 11 



and their adaptations and peculiar purposes; to 

 examine the proirress of inorganic matter in its 

 (iiU'crent processes of chanije, till it attain its ulti- 

 niaic and highest destination, — its subserviency to 

 liie purposes of" man? 



Many o|" tlie sciences are ardently pursued, and 

 considered as proper objects ofstudy for all refined 

 minds, merely on account oi" the intellectual plea- 

 sure they atfbrd; merely because they enlarge our 

 views of nature, and enable us to think more cor- 

 rectly with respect to the beings and objects sur- 

 rounding us. How much more, then, is this de- 

 partment oC inquiry worthy of attention, in which 

 the pleasure resulting from the love of truth and 

 of knowledge is as great as in any other branch 

 of philosophy, and in which it is likewise connect- 

 ed with much greater practical benefits and ad- 

 vantages? "A7/!i7 est melius, nihil vberius, nihil 

 homine libero dignius.^^ 



Discoveries made in the cultivation of the earth 

 are not merely for the time and country in which 

 they are developed, but they may be considered as 

 extending to future ages, and as ultimately tending 

 to benefit the whole human race; as affording sub- 

 sistence for generations yet to come ; as multiply- 

 ing life, and not only multiplying life, but likewise 

 providing for its enjoyment. 



LECTURE II. 



OF THE GEXERAI^ POWERS OF MATTER WHICH 

 INFLUENCE VEGETATION. OF GRAVITA- 

 TION, OF COHESION, OF CHEMICAL AT- 

 TRACTION, OF HEAT, OF LIGHT, OF ELEC- 

 TRICITY, PONDERABLE SUBSTANCES, ELE- 

 3IENTS OF MATTER, PARTICl/LAR LY THOSE 

 FOUND IN VEGETABLES, LAWS OF THEIR 

 COMBINATIONS AND ARRANGE3IENTS. 



The great operations of the farmer are directed 

 "towards the production or improvement of certain 

 classes of vegetables; they are either mechanical 

 or chemical, and tire, consequently, dependent 

 upon the laws which govern common matter. 

 Plants themselves are, to a certain extent, sub- 

 milted to these laws; and it is necessary to study 

 their efl'ects, both in considering the phenomena 

 of vegetation, and the cultivation of the vegetable 

 kingdom. 



One of the most important properties beloncinof 

 to matter is gravitatiun, or the power by which 

 masses of matter are attracted towards each other. 

 It is in consequence of gravitation that bodies 

 thrown inio the atmosphere fall to the suiface of 

 the earth, and that the different parts of the globe 

 Tire preserved in their proper positions. Gravity 

 is exerted in proportion to the quantity of matter. 

 Hence all bodies placed above the sui face of the 

 earth fall to it in right lines, which, if produced, 

 would pass through its centre; and a body falling 

 near a high mountain is a little bent out of the 

 perpendicular direction by the attraction of the 

 mountain, as has been shown by the experiments 

 of Dr. Maskelyne on Schehallien. 



Gravitation has a very important influence on 

 the growth of plants; and it is rendered probable, 

 by the experiments of Mr. Knight, that they owe 

 the peculiar direction of their roots and branches 

 almost entirely to this force. 



That gentleman fixed some seeds of the garden 

 bean on the circumlijrence of a wheel, which in 

 one instance was placed vertically, and in the other 

 horizontally, and made to revolve, by means of 

 another wheel worked by water, in such a manner, 

 that the number of the revolutions could be regu- 

 lated; the beans were supplied with moisture, and 

 were placed under circumstances fiivorable to ger- 

 mination. The beans all grew, notwithstanding 

 the violence of revolution, which was sometimes 

 as much as 250 revolutions in a minute on the 

 vertical wheel, which always revolved rapidly, 

 and with little variation of velocity; t lie radicles, 

 or roots, pointed precisely in the direction of radii 

 in whatever direction they were first placed. The 

 germs took precisely the opposite direction, and 

 pointed to the centre of the wheel, where they 

 soon met each other. Upon the horizontal wheel, 

 the conflicting operation of gravitation and centri- 

 fugal force, occasioned the germs to form a cone, 

 more or less obtuse, according to the velocity of 

 the wheel, the radicles always taking a course 

 diametrically opposite to that taken by the germs, 

 and, consequently, pointing as much below as the 

 germs pointed above the plane of the wheel's 

 motion. 



These facts afford a rational solution of this cu- 

 rious problem, respecting which different philoso- 

 phers have given such different opinions; some re- 

 fijrring it to the nature of the sap, as De la Hire; 

 others, as Darwin, to the living powers of the 

 plant, and the stimulus of air upon the leaves, 

 and of moisture upon the roots. The efiect is now 

 shown to be connected with mechanical causes; 

 and there seems no other power in nature to which 

 it can with propriety be referred, but gravity, 

 which acts universally, and which must tend to 

 dispose the parts to take a uniform direction.* 



If plants in general owe their perpendiciilar di- 

 rection to gravity, it is evident that the number of 

 plants upon a given part of the earth's circum- 

 ference cannot be increased by making the surface 

 irregular, as some persons have supposed. Nor 

 can more stalks rise on a hill than on a spot equal 

 to its base; for the slight efiect of the attraction 

 of the hill, would be only to make the plants de- 

 viate a very little from the perpendicular. Where 

 horizontal layers are pushed forth, as in certain 

 grasses, particularly such as the fiorin, lately 

 brought into notice by Dr. Richardson, more food 

 may, however, be produced upon an irregular sur- 

 face; but the principle seems to apply strictly to 

 corn crops. 



The direction of the radicles and germens is 

 such, that both are supplied with food, and acted 

 upon by those external agents which are necessa- 

 ry for their developement and growth. The roots 

 come in contact with the fluids in the ground; the 

 leaves are exposed to light and air; and the same 

 grand law which preserves the planets in their or- 

 tiits is thus essential to the llinctions of vegetable 

 life. 



When two pieces of polished glass are pressed 

 together, they adhere to each other, and it requires 

 some, force to separate them. This is said to de- 

 pend upon the attraction of cohesion. The same 



* Fig. 1. represents tfie case in which tfic liorizon- 

 tal wiieef performed 2.50 revolutions. 



Fi<;. 2. represents the form of the experiment when 

 the vertical wheel was made to perform 150 revolu- 

 tions in a minute. 



