478 Miscellaneous Intelligence. 



tion of the hydrogen," it is said, " is caused by abstracting' a por- 

 tion of the caloric from the oxygen, effected by the platina, the 

 smaller the laminae of the metal are, the more readily is the incan- 

 descence produced." Spongy platina for the lamps for instantaneous 

 light, is prepared of great power, by moistening the muriate of am- 

 monia and platina with a concentrated solution of ammonia ; the 

 paste formed is to be heated to redness in an earthen or platina 

 crucible. — Hensmans Repertoire — Phil. Mag. N. S. ii. 388, 



26. New Metals. — Professor Osann, of Dorpat, is said to have 

 discovered three new metals in the crude platina, obtained from 

 the Uralian mountains. One, which has occurred only in one spe- 

 cimen of the ore, resembles osmium in some of its compounds. 

 The second forms white acicular crystals from a nitro-muriatic acid 

 solution ; these, when heated, being softened and reduced. The 

 third is insoluble in nitro-muriatic acid, and, by a particular pro- 

 cess yields a dark green- coloured oxide. The account as yet giyen 

 of these substances is not precise enough to allow of any judgment 

 respecting their claim to the character of new metals. 



27. Analysis of Porcelain, Pottery, Sfc. by M. Berthier. — Earthen- 

 ware manufactures are divided by M. Berthier into three kinds, 

 those of 1. Porcelain; of 2. Pottery; and of 3. Crucibles, Bricks, 

 &c. The following is the composition of certain porcelains : 



Porcelain. 



Sevres. English. Piedmont. Tournay. 



(i.) (li) (iii-) (iv.) 



Silica 0.596 0.770 0.600 0.753 



Alumina 0.350 0.086 0.090 0.082 



Potash 0.018 .. .. Innxn 



Soda r^^^ 



Lime 0.024 0.012 0.016 0.100 



Magnesia 0.070 0.152 



Water 0.008 0.056 0.136 0.006 



0.996 0.994 0.994 1.000 



(i.) Sfevres service — Paste strongly heated. It is formed from 

 0.63 washed kaolin of Limoges ; 0.105 quartz sand; 0.052 Bou- 

 geval chalk ; 0.21 of the fine sand obtained from kaolin by wash- 

 ing, and which is a mixture of quartz and felspar. The glaze of 

 this ware is made of a rock composed of quartz and feldspar. When 

 reduced to a fine powder, it is found to be composed of silica .730, 

 alumine 162, potash 84, water 6 : it fuses into a perfectly transpa- 

 rent and colourless glass. 



(ii.) Worcester porcelain — Paste taken from the workshops, 

 unbaked. 



(iii.) Porcelain of Piedmont — Paste dried. The base of this 

 manufacture is the magncsite of Baldissero. 



(iv.) Porcelain of Tournay — Clay, chalk, and soda enter into iU 

 composition. It is very fusible, but not very fragile. 



