SCIENCE. 



195 



calcium borate, inner crystals, some of which are very 

 beautiful and characteristic, especially by polarised light. 



SILICON BORATE. 



(10). I now feel that it was necessary to confirm these 

 qualitative experiments by quantitative ones, and to estab- 

 lish the existence of this new substance, whatever it may 

 be, which, eliminated from calcium hydrate, causes opales- 

 cence in a bead of boric acid before the blowpipe without at 

 all lessening the due proportion of calcium in the borate 

 ball formed — upon the reliable authority of the balance. 



(11). As I invariably found that pure chemically prepared 

 silicalxom Dr. Schuchartt, of Gorlitz in Prussia, affbrds/«- 

 se an orange flame before the blowpipe, and opalescence to 

 a bead of boric acid containing a calcium borate ball (7) ; I 

 chose this single substance, as left by the best analytical 

 chemists in Europe to see if I could not resolve it — by 

 weighing them — into two substances, and I submit that the 

 results (the truth of which any chemist may easily ascertain 

 for himself in his own laboratory by simply repeating these 

 experiments) are sufficiently constant, under varying condi- 

 tions, to warrant the immediate consideration of the unbi- 

 goted chemist. 



URANIUM BORATE. 



I. DR. SCHUCHARTT'S SILICA FROM GORLITZ. 



Mqrs. 

 (1). Si 2 dissolved in a calcium borate ball, B. B. . . 2.5 



(2). Weight of siliceous ball 18.5 



(3). Weight of siliceous ball after extraction from 1st 



bead (2) 30. o 



(4). Weight of siliceous ball after extraction from 3d 



bead 26.7 



(5). Weight of siliceous ball after extraction from 5th 



bead, when no more opalescence was given off. 23.0 



II. POWDER OF PURE ROCK CRYSTAL. 



(1). Si 2 dissolved in a calcium borate ball, B. B. . . . 2.5 



(2). Weight of siliceous ball 22 . 3 



(3). Weight of siliceous ball after extraction from 1st 



bead 3°- 7 



(4). Weight of siliceous ball after extraction from 4th 



bead 27.8 



(5). Weight of siliceous ball after extraction from 5th 



bead . 24 . 8 



III. THE SAME AS ABOVE. 



(1). Si 2 dissolved in a calcium borate ball 2.5 



(2). Weight of siliceous ball 29.0 



(3), Weight of siliceous ball after extraction from 1st 



bead 38 . 5 



(4). Weight of siliceous ball after extraction from 5th 



bead 34 . 1 



IV. MEXICAN OPAL (nearly transparent). 



(1). Si 2 dissolved in calcium borate ball 2.5 



(2). Weight of siliceous ball 25.8 



(3). Weight of siliceous ball after extraction from 1st 



bead 37.5 



(4). Weight of siliceous ball after extraction from 3d 



bead 33.5 



(5). Weight of siliceous ball after extraction from 6th 



bead 28.8 



V. Mexican opal {again). 



(1). Si 2 dissolved in calcium borate ball 2.5 



(2). Weight of siliceous ball 18.0 



(3), Weight of siliceous ball after extraction from 1st 



bead 30.0 



(4). Weight of siliceous ball after extraction from 4th 



bead 28.5 



(5). Weight of siliceous ball after extraction from 5th 



bead , 26 . 9 



INCREASE OE WEIGHT. 



Experiment I. 



Mqrs. Mqrs. Mqrs. 

 Operation (5) — (2) = 23 — 18.5 = 4.5. 



Mqrs. Mqrs. Mqrs. 



Weight of Opalescent Matter = (3) — (5) = 30 — 23= 7. 

 Experiment II. 



Operation (5) — (2) = 24.8 — 22.3 = 2.5. 



Weight of Opalescent Matter = (3) — (5)=30.7 — 24.8 = 5.9 



Experiment III. 



Operation (4) — (2) = 34.1 — 29.0 = 5.1. 



Weight of Opalescent Matter = (3) — (4) = 38.5—34.1=4.4. 



Experiment IV. 



Operation (5) — (2) = 28.8 — 25.8 — 3.0. 



Weight of Opalescent Matter =(3)— (5) = 37. 5 — 23.8 = 13,7. 



Expo intent V. 



Operation (5)— (2) = 26.9— 18.0=8.9. 



Weight of Opalescent Matter = (3)— (5)=30.0— 26-9=3.1. 



Note. — The illustrations accompanying this article are 

 made from rough sketches of crystals drawn, without cam- 

 era luada from the microscopes. The shaded parts indicate 

 color. The crystals were made by dissolving the oxide BB 

 in a calcium borate ball held as a bead on platinum wire ; 

 crushing this bead to powder, and applying some of this 

 powder BB to a boric acid bead.* 



Mr. Barkas, of Newcastle-on-Tyne, Eng., has taken a 

 very practical method of encouraging observational Astron- 

 omy, by offering to meet any of his townsmen who may be 

 sufficiently interested and show them Jupiter, Saturn and 

 other objects through an excellent telescope. From small 

 beginnings great things often arise, and we should not be 

 surprised if this offer, to be at a certain spot on a given 

 night, led to the establishment of an observing society in 

 Newcastle. 



* In forwarding the above communication to " Science," Col. Ross 

 states that it was originally prepared to be read at the recent meeting 

 of the British Association. — (Ed.) 



