194 



SCIENCE. 



a tendency to take the globular form, because it is the form 

 in which the particles are at the least mean distance from 

 the centre of gravity. As most oxides do not dissolve in 

 boric acid, if the latter in its viscous state has very nearly 

 the same specific gravity as the fused oxide, but is not 

 miscible with it. This forms a ball with a tendency to 

 occupy the centre of the bead, as oil does in water or water 

 in oil, and the microscope now showed me, with reference 

 to silica, that what I had supposed, looking through an 

 ordinary lens, to be siliceous crystals adhering to calcium 

 borate balls, formed by the mineral Wollastonite in boric 

 acid were, in reality, thousands of inner transparent balls 

 floating inside each calcium borate ball. 



TUNGSTONE BORATE. 



Similarly, therefore, it may be assumed, that a second 

 borate, if it is not miscible with the first borate, but if it has 

 a stronger cohesion, will take the place of an inner bead, 

 and so it may be presumed with a succession of oxides. 



(5). This assumption however demands the concession 

 that each inner ball is a single borate, notwithstanding that 

 it must obviously derive its boric acid from the containing 

 borate ball, which, being ascertained, as in the case of cal- 

 cium, to possess only its definite proportion of that acid, 

 must in that case take the exact proportion of boric acid 

 from the outer bead, which it has to give up to the inner 

 ball. 



TUNGSTONE BORATE. 



(6). To determine therefore, by actual experiment, if the 

 inner ball in the case of Wollastonite was a silico-borate of 

 calcium or a simple borate, I made a large calcium-borate 

 ball with pure eggshell lime, in a bead of boric acid ; ex- 

 tracted it by boiling the bead in water ; made a bead on new 

 platinum wire with the extracted ball ; and, applying pure 

 silica to it before the blowpipe, found that it would not now 

 form balls within the calcium borate, although it would do 

 so readily enough when the whole was surrounded by a 

 bead of boric acid. On the contrary silica, zirconia, ytlria, 

 glucina, alumina, etc — all the " earths " in fact, which will 

 not form balls p'r se in boric acid, dissolve rapidly and 

 transparently in calcium borate when held as a bead by it- 

 self on platinum wire, but form balls within it when the 

 whole is surrounded by a bead of boric acid, so that I sub- 



mit the conclusion, that as regards silicate of lime, the 

 inner balls may be composed of anew substance, Silicon 

 borate, or alternatively silicate of boron. 



(7.) I found that, as in the case of calcium hydrate (2) si- 

 lica, however chemically pure, invariably gave off a certain 

 amount of matter which caused opalescence in the boric- 

 acid bead, before forming the inner balls above mentioned, 

 from which phenomenon I argue that, if silicon borate is 

 presumed to be formed, it is reasonable to infer that what 

 we call silica is in reality silicon hydrate, and that a regular 

 chemical interchange of components takes place. 



TITANIUM BORATE. 



(8.) Alongside the inner "silicon borate" balls in the 

 large calcium borate balls afforded by the mineral Wollas- 

 tonite (from a Freibourg Cabinet) in a bead of boric acid, 

 are numerous spherical enclosures, exhibiting under a 

 j^-inch objective, a brownish amethystine color, similar to 

 that imparted by manganese to borax held in an oxidising 

 flame, and, on referring to the account of this mineral in 

 Dana's " System of Mineralogy, 1877," I find that from .2 

 to .9 of manganic dioxide are supposed to have been de- 

 tected in certain specimens by Stromeyer, Weidling, and 

 Whitney. But manganese itself forms balls per se in a 

 bead of boric acid, and in no case, within my observation, 

 do ball-forming oxides produce these inner balls in cal- 

 cium-borate ; indeed, from the ordinary law of physics, 

 such a circumstance is an impossibility, and I have mounted 

 boric acid beads of the single colored balls derived from 

 manganese dioxide, and manganese silicate with lime, 

 beside a bead containing the triply-enclosed colored balls 

 derived from Wollastonite, -vhich I would submit therefore, 

 may be due to a New Earth of the silica type. 



MANGANESE CALCIUM BGRATK. 



a. Manganese Borate— one Calcium Borate Ball accidentally present 



(9.) I would only add here that the acid oxides, as W0 3 , 

 Ti0 3 . etc., which also fail to form balls per se, in boric acid, 

 remaining there before the blowpipe in fragments, colored 

 or not, as the case may be, form, instead of inner balls in 



