Intelligence and Miscellaneous Articles, 141 



vessel, capable of holding four ounces ; it was furnished with a cover j 

 it was kept in a place which was perfectly dry at all times. An 

 equal quantity of the same extract (B) was put into a similar vessel 

 covered merely with linen j this vessel was placed on a stand, at 

 about four feet above ihe ground in a place used occasionally for 

 distillation, and in which large quantities of water were evaporated, 

 so that the air contained more or less moisture; in the same place 

 and by the side of the extract of quassia, and in a similar vessel also 

 covered with linen, an ounce of extract of gentian was placed (C), 

 which is well known to contain no nitre. All the vessels thus placed 

 were kept so for a whole year, at the expiration of which the three 

 extracts were examined. 



The extract (A) was rather dried and had lost ^7 grains, Treated 

 repeatedly for half an hour, with boiling alcohol of sp. gr. 837, it 

 yielded 8 grains of nitrate of potash. 



The extract (B) was much softened and had increased 90 grains in 

 weiglit, it was heated in a salt water bath, in order to restore it as 

 nearly as possible to its original consistence, it was then treated 

 like the foregoing. It yielded 10^ grains of nitrate of potash. 

 Lastly, the extract (C), that of gentian, had increased 38 grains in 

 weight. Submitted to the same treatment as the preceding, it did 

 not yield an atom of nitre. 



Thus in the extract (B,) which was exposed to moist air, the increase 

 of nitrate of potash was 2| grains, in the space of a year, whilst the 

 extract (C), which had been placed in the same circumstances, and in 

 which there exists no azotized matter like that of quassia, no por- 

 tion of nitre was formed. M. Planche concludes that after these re- 

 sults it is difficult not to attribute the newly-formed nitre in the ex- 

 tract of quassia to the azotized matter which it contains. — Journal 

 de Pharmacies November 1837. 



METHOD OF DISSOLVING IRIDIUM. BY M. FELLENBERG. 



M. Fellenberg remarks that by Wcshler's method of separating 

 iridium there is obtained a double alkaline chloride of iridium, 

 whereas by his process, which is as follows, a simple chloride is ob- 

 tained which is very soluble in water- This process is founded on 

 the fact that chlorine converts the greater number of metallic sul- 

 phurets into corresponding chlorides. 



Iridium, separated from the ore of platina, containing osmium or 

 not, is to be reduced to the finest powder in an agate mortar; upon 

 this, the success of the process mainly depends. This powder is 

 then to be mixed with three times its weight of flowers of sulphur, six 

 times its weight of carbonate of potash or dry carbonate of soda, 

 then heated in a well closed porcelain crucible, and kept in a strong 

 red heat till no vapour of sulphur or of sulphurous acid is percep- 

 tible. When the crucible is cold, the mass, which is of a black-brown 

 colour, is reduced to powder, and washed with boiling water till it 

 ceases to produce any effect upon a solution of lead. The sulphuret 

 of iridium is easily separated from the liquor by simple decantation ; 

 it is then to be thoroughly dried and reduced to a fine powder. 



This is to be placed in a tube with a bulb, which is to be con- 



