The companion to the compound, ox-hydrogen, and solar microscopes ... / [Charles Gould].

  • Gould, Charles, 1909-1998
Date:
1835
Catalogue details

Licence: Public Domain Mark

Credit: The companion to the compound, ox-hydrogen, and solar microscopes ... / [Charles Gould]. Source: Wellcome Collection.

    21/90 (page 13)
    ACTIVE MOLECULES. In Organic and Inorganic Bodies, discovered by Robert Brown, Esq. F.R.S. $'C. Sfc. fyc. This indefatigable gentleman, in prosecuting his elabo- rate researches into the vegetable kingdom, was led to infer, (from circumstances connected with the investigation of the pollen of plants suspended in water,) that the same active molecules might likewise exist in inorganic bodies ; he has not been disappointed, having succeeded in separat- ing them from almost every known substance, such as minerals, glass, common dust, soot, &c. &c.; indeed the principal exceptions are oil, resin, wax, sulphur, such of the metals as could not be reduced to that minute state of division necessary for their separation, and, finally, bodies soluble in water. The process of obtaining a satisfactory view of these mi- nute active molecules is exceedingly simple, and is as fol- lows: with the head of a pin place a small drop of distilled or filtered water upon a slip of glass, then apply the head of the pin, (again dipped in the water,) to the substance from which the molecules are to be separated, which is effected by a slight friction : afterwards immerse the head of the pin in the water upon the slip of glass, gently agi- tating it; this will occasion the molecules to be transferred to the water upon the glass, which is then in a state to be submitted to the deep powers of the microscope: to sepa- rate the molecules from the glass itself, either pound, it very fine, or gently rub together the unpolished edges of two pieces, having previously wetted them—the produce can then be transferred to a drop of water. The ti gure of the molecules is spherical: they are so mi- nute, that four hundred millions of them would not occupy greater space than a superficial square inch. Their motionr is very vivid, and consists, not only of a change of place in the fluid, manifested by alterations in their relative posi- tions, but also, not unfrequently, of a change of form in the particle itself; each molecule appears to revolve upon its axis : in fact, the whole of the motions are very similar