364 Mr Brown 07i the Existence of Active Molecules 



quantity, especially in London, is entirely composed of these 

 molecules. 



One of the substances examined, was a specimen of fossil 

 wood, found in Wiltshire oolite, in a state to burn with flame ; 

 and as I found these molecules abundantly, and in motion in 

 this specimen, I supposed that their existence, though in smaller 

 quantity, might be ascertained in mineralized vegetable remains. 

 With this view a minute portion of silicified wood, which ex- 

 hibited the structure of Coniferae, was bruised, and spherical 

 particles, or molecules in all respects like those so frequently 

 mentioned, were readily obtained from it ; in such quantity, 

 however, that the whole substance of the petrifaction seemed to 

 be formed of them. But hence I inferred that these molecules 

 were not limited to organic bodies, nor even to their products. 



To establish the correctness of the inference, and to ascertain 

 to what extent the molecules existed in mineral bodies, bepame 

 the next object of inquiry. The first substance examined was 

 a minute fragment of window-glass, from which, when merely 

 bruised on the stage of the microscope, I readily and copiously 

 obtained molecules agreeing in size, form, and motion with those 

 which I had already seen. 



I then proceeded to examine, and with similar results, such 

 minerals as I either had at hand or could readily obtain, inclu- 

 ding several of the simple earths and metals, with many of their 

 combinations. 



Rocks of all ages, including those in which organic remains 

 have never been found, yielded the molecules in abundance. 

 Their existence was ascertained in each of the constituent mi- 

 nerals of granite, a fragment of the Sphinx being one of the spe- 

 cimens examined. 



To mention all the mineral substances in which I have found 

 these molecules, would be tedious ; and I shall confine myself 

 in this summary to an enumeration of a few of the most re- 

 markable. These were both of aqueous and igneous origin, 

 as travertine, stalactites, lava, obsidian, pumice, volcanic ashes, 

 and meteorites from various- localities*. Of metals I may 

 mention manganese, nickel, plumbago, bismuth, antimony, and 



■ I have since found the molecules in the sand-tubes, formed by lightning, 

 from Drig in Cumberland. 



