HISTORY OF ZOOPHYTOLOGY. 41? 



duced," he says, " are undoubtedly replete with mineral salts, 

 some whereof near their surface, being dissolved by the sea- 

 water, must consequently saturate with their saline particles 

 the water round them to a small distance, where blending 

 with the stony matter with which sea-Avater always abounds, 

 little masses will be constituted here and there and affixed to 

 the rocks. Such adhering masses may be termed roots : which 

 roots attracting the saline and stony particles, according to 

 certain laws in nature, may produce branched or other figures, 

 and increase gradually by an apposition of particles ; becom- 

 ing thicker near the bottom where the saline matter is more 

 abounding, but tapering or diminishing toward the extremities, 

 where the mineral salts must be fewer, in proportion to their 

 distance from the rock whence they originally proceed. And 

 the diiferent proportions of mineral saline particles, of the 

 stony or other matter wherewith they are blended, and of 

 marine salt, which must have a considerable share in such for- 

 mations, may occasion all the variety we see. Nor does it 

 seem more difficult to imagine that the radiated, starry, or 

 cellular figures along the sides of these corals, or at the ex- 

 tremities of their branches, may derive their production from 

 salts incorporated with stony matter, than that the curious 

 delineations and appearances of minute shrubs and mosses on 

 slates, stones, &c., are owing to the shootings of salts inter- 

 mixt with mineral particles : and yet these are generally 

 allowed to be the work of mineral steams or exhalations ; by 

 which must, I think, be meant the finest particles of some 

 metal or mineral incorporated with and brought into action by 

 a volatile penetrating acid, which carrying them along with it 

 into the fissures at least, if not into the solid substance of 

 such stones or slates, there determines them to shoot into 

 these elegant branchings ; after the same manner, and fre- 

 quently in the same figures, as the particles of mercury, cop- 

 per, &c., are disposed and brought together by the salts in 

 aqua fortis.'"'^^ 



But the progress of truth, although it may be delayed by 

 opposition, cannot be permanently arrested. The converts to 

 the new doctrines were indeed few, but much had been done 



* Employment for the Microscope, pp. 218 — 220. Lend. 1753. 



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