196 Miscellaneous Intelligence. 



The balsamic odour of yarrow is principally due to the volatile 

 oil, and in part to the resinous substance. The taste depends upon 

 the tannin, the extract, the resinous parts, the nitrate, and muriate 

 of potassa. The sulphur is doubtless contained in the albumen. 

 The bitterness of the leaf of yarrow, which Bucholz and Bernhardi 

 attributed to a peculiar extract, is due rather to the chlorophyle, 

 to the resin, and to the salts. — Trommsdorff, Neues Journal der 

 Pharmacie. 



40. Researches respecting Platina, by M. Dobereiner. — a. When 

 chloride of platina is dissolved in about 300 parts of water, and 

 the solution rendered sour with muriatic acid, if zinc, in a metallic 

 state, be plunged into it, a powder is gradually precipitated, which 

 chemists have always, but doubtless erroneously, (according to M. 

 Dobereiner,) considered as pure platina ; for in a state of dryness 

 this body becomes warm, and assumes a brighter colour, if it be 

 exposed to the air and moistened with alcohol ; lastly, it becomes in- 

 candescent, particularly after havingbeen treated with nitric acid, when 

 (in contact with the air) it is exposed to a current of hydrogen gas. 



b. When chloride of platina has been treated several times suc- 

 cessively with absolute alcohol, at a mild heat, there is obtained at 

 last a brown mass, which easily burns at a higher temperature, but 

 which, dissolved in a great quantity of alcohol, affords a liquid very 

 fit for being laid upon a glass, so as to form platina mirrors. For 

 this purpose, dip the glass in the alcoholic solution, so that this last 

 may be uniformly diffused ; then bring it to a red heat in the flame 

 of a spirit lamp. The coat of platina thus produced affords the 

 brilliancy of a mirror, and adheres so well, that it is impossible 

 to detach it. But if a mirror of this sort be dipped in water mixed 

 with muriatic acid, and at the same time a plate of zinc be placed 

 in the liquid, the whole coat of platina adhering to the glass dissolves 

 almost instantaneously. 



c. The decomposition of the oxide of carbon, by the dry oxi- 

 sulphuret of platina, has always been observed by M. Dobereiner, 

 although others have doubted the fact. He has found, that from 

 12 to 15 grains of the oxisulphuret (obtained by exposing sulphuret 

 of platina prepared in the humid way to the action of the air during 

 several weeks) are sufficient to decarbonate a cubic inch of the 

 carbonic oxide gas, and that there remains exactly, in this experi- 

 ment, half a cubic inch of carbonic acid gas, which proves (says 



*M. Dobereiner), that the oxide of carbon is composed of equal vo- 

 lumes of carbonic vapour, and of carbonic acid gas, — the proto- 

 carbonated and deutocarbonated hydrogen act differently ; they are 

 absorbed in great part by the oxisulphuret of platina, and trans- 

 formed into acetic acid, without any influence of atmospheric air. 



d. The suboxide of platina affords an excellent method of dis- 

 covering the presence of alcohol, dissolved either in atmospheric 

 air, or in any liquid ; even the quantity may be determined by means 

 of it. Thus, putting a drop of alcohol into a vessel of the size of 



