434 Scientific Intelligence* 



9 



u\il\e\n an excess of the precipitant. Alkaline carbonates yield precip- 

 itates soluble in an exces^of ihe precipitant; the solution in carbonate 

 of soda is not precipitated by boiling ; that in carbonate of ammonia, 

 on the contrary, is completely precipitated, and the precipitate is not 

 a<fain dissolved in an excess of the carbonate. 



Oxalic acid produces in a neutral or acid solution, a thick white pre- 

 cipitate which is Insoluble in free oxalic, but soluble in a large excess j 

 of chlorohydric acid with the aid of heat. A concentrated solution of 

 sulphate of potash gradually produces a precipitate which is however 

 again dissolved by more water or by HCI. Ferrocyanid of potassium 

 produces in a neutral solution of oxyd of donarium, a nearly flesh col- 

 ored precipitate soluble in acids. Carbonate of baryta precipitates the 

 oxyd completely in the cold, Sulphid of ammonium produces in so- 

 lutions of donarium a dark green flocky precipitate which is insoluble 

 in an excess of the precipitate : HCI decomposes it with evolution of 

 sulphydric acid gas. Red ferrocyanid of potassium, tincture of gall- 

 nuts and sulphydric acid produce no precipitate ; organic substances, 

 such as tartaric acid, almost entirely prevent the precipitation of the 

 oxyd by caustic alkalies. The oxyd of donarium is not rendered solu- 

 ble by fusion with caustic or carbonated alkalies ; fused with bisulphate ^ 

 of potash, however, a flocky matter is obtained which is soluble in ex- • 

 cess of water, and appears to be the double sulphate of donarium and 

 potash. Before the blowpipe the oxyd of donarium exhibits no very 

 characteristic reactions. With soda it forms a globule in which the 

 particles of the oxyd appear undissolved; with borax and the double 

 phosphate it gives a yellowish pearl which becomes colorless on cooling 

 and in which the particles of the oxyd are easily recognized. A mix- 

 ture of the hydrated oxyd and sugar was ignited and then a current of ♦ 

 dry chlorine passed over the mass heated to redness in a glass tube ; 

 white vapors were formed which condensed to a voluminous mass per- 

 fectly soluble in water, these were doubtless the anhydrous chlorid 

 D02CI3. The equivalent of donarium was determined by an analy- j 

 sis of the sulphate which gave for the metal 997'4, upon the assumption ' 

 (which the author considers highly probable) that the oxyd is a sesqui- 

 oxyd. — Pogg. Ann., Ixxxii, 561. w, g. 



10. An Account of an apparatus for producing Attrition helioeen the 

 Surfaces of Siliceous Sto?ies in Vacuo^ or in Gaseous Media^ and for 

 Determining ivhether the Consequent Odor and Corruscations are due 

 to Ozonification ; Communicated at a meeting of the Franklin Institute, 

 April 17, 1851, by Dr. Hare, Member of the Insthute, Emeritus Pro- 

 fessor of Chemistry in the University of Pennsylvania, and Associ- 

 ate of the Smithsonian Institution, (Journal of Franklin Institute). — Dr. 

 Hare submitted to the attention of the meeting, an apparatus for ascer- 

 taining whether the phenomena attending the attrition of pieces of 

 silex, when rubbed briskly together, had any thing in common with 

 those ascribed by Schonbein, to a supposed new halogen body, named 

 by him Ozone, and made the following remarks. The odor which re- . 

 suits from electrical excitement, or discharges between oppositely elec- 

 trified bodies, had long been familiar to electricians. This odor is of a 

 nature to recall that of phosphorus to all acquainted with the smell 



