EXTRAORDINARY PHILOSOPHICAL DISCOVERY.
WE have been exceedingly struck by the perusal of an essay, which has been lately printed, and privately circulated through the scientific channels of London, announcing the singular discovery that there exist in all bodies, whether organic or inorganic, certain particles ("active molecules") which are constantly in a state of motion. Before we offer any account of this singular and unexpected phenomenon, it may be necessary to secure the attention and confidence of our readers, by stating, that the author is Mr. ROBERT BROWN; a gentleman well known throughout Europe as the most distinguished botanist of the age, and whose accuracy on all subjects of scientific investigation it would be little less than heresy to question. The observations, of which the author has given us a summary, were all made with a simple microscope, the focal length of which was about hd of an inch. His original object was the examination of the structure of the pollen of plants ; and it was while viewing the particles obtained from that of Clarckia pulchella, immersed in water, that he first observed the motions which have led to such curious conclusions. "These motions," he tells us, "not only consisting of change of place in the fluid, manifested by alterations in their relative positions, but also, not unfrequently, of a change of form in the particle itself; and, in a few instances, the particle was seen to turn on its longer axis." These motions were such as to satisfy the author, after frequently repeated observations, that they were neither from currents in the fluid, nor from its gradual evaporation, but "belonged to the particle itself." The discovery of motion in living plants is by no means novel ; nor does Mr. Brown, as far as this goes, claim any merit for originality; but he has extended the sphere of our knowledge in this department, by showing that such motions belong to the particles of the pollen of every living plant submitted to examination. Reflecting on these facts, he was disposed to believe that these active particles were in reality the supposed constituent or elementary molecules of organic bodies, first so considered by Buffon and Needham, and more recently by Dr. Milne Edwards, who has revived the doctrine, and supported it with Much interesting detail ; and he therefore proceeded to examine the various animal and vegetable tissues whether living or dead, and with equal success. By merely bruising these substances in water, he says, " I never failed to disengage the molecules in sufficient numbers to ascertain their apparent identity in size, form, and motion, with the smaller particles of the grain of pollen." He also examined various products of organic bodies, particularly the gum-resins, &c. Here our wonder necessarily increases, and takes a new direction. Hitherto the idea of motion has been associated with that of life, and is consistent with our previous views; but we are now called upon to extend our notions of vitality to gum-resins and the products of living vegetables, or, as an alternative, we must seek for the source of motion amongst the agencies which influence inert matter. But our readers are now only entering upon the field of mystery and wonders : what will they say, when they are informed that the mineral kingdom abounds in moving particles ?ay, even the dust of London ! Fearing that you may fancy We are hoaxing you, hear the author's own words—" I remark here also, partly as a caution to those who may hereafter engage in the same inquiry, that the dust or soot deposited on all bodies in such quantity, especially in London, is entirely composed of these molecules." To establish the correctness of the inference that these molecules were not limited to organic bodies, nor even to their products, Mr. Brown examined a minute fragment of window-glass, from which, when merely bruised on the stage of the microscope, he readily and copiously obtained molecules, agreeing in size, form, and mormer, with those he had already observed! In conclusion, he enumerates the principal substances from which these moving molecules could not be obtained: these exceptions are oil, resin, wax, and sulphur, such of the metals as he could not reduce to that minute state of division necessary for their separation, and finally, bodies soluble in water ; but our readers will immediately perceive that such are rather apparent than real exceptions to his general law.
Having given a brief outline of this most curious, and at present mysterious discovery, we may perhaps be expected to offer some opinion, or at least to hazard some sort of conjecture. In the first place, can such motion belong to the particle itself ?—may it not be the result of some foreign cause ? Mr. Brown is satisfied upon this point, and he tells us that he is quite certain that no source of fallacy can exist ; but the wisest philosopher has erred, and we would with all humility inquire whether these motions may not possibly be connected with the extrication of minute bubbles of air from the water ? Almost every substance in a state of minute division has the power of producing such a separation. We will illustrate this by one example : after a glass of soda water, or of champagne, has ceased to effervesce, a small quantity of powdered sugar (sand would answer the same purpose) will re-excite it into action. But suppose, for argument's sake, that no source of fallacy exists, and that the particles do acivally possess an inherent and independent principle of motion ; in such a case, we must infer either the presence of life, or of attraction, for we know of no other sources of motion—magnetism and electricity are included under the idea of the latter. We have next to inquire whether the phenomena in question are in accordance with the known laws of such a force ; and we have no hesitation in saying, that in the present stage of the inqui.y we cannot derive the least assistance from such a reference.
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