74 Intelligence and Miscellaneous Articles. 



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yields by evaporation a blue mass of oxide of molybdenum, similar to 

 that obtained by the same means from the yellow lead of Bleyberg. 

 When tried by the blow-pipe no difference is found between the two 

 oxides. 



It results from the preceding researches, that far from being 

 composed entirely of chromic acid and oxide of lead, as Professor 

 Johnston has stated, the red variety of yellow lead consists princi- 

 pally of molybdate of lead ; it may however contain a little chromic 

 acid. The presence of this acid is readily explained by the ana- 

 logous composition of chromic and molybdic acids. — Annates des 

 Mines, tome xvii. 



[Note. — In our last Number the measure of the angles of leu- 

 cophan was stated as given in the Journal ftir praktische Chemie ; 

 the reader will perceive that there must be some error in the state- 

 ment, but which we have not the means of correcting. With respect 

 to andesine, also, we followed the same authority in mentioning it 

 to have been found " in twin crystals very similar to albite," yet it 

 is stated to be a leucite : this is not very intelligible when we re- 

 collect that albite has a doubly oblique prism, and leucite a cube, as 

 their primary forms. — Ed.] 



METHOD OF DISTINGUISHING BETWEEN WEAK SOLUTIONS OF 

 NITRATES AND CHLORATES. BY M. VOGEL, JUN. 



When a few drops of tincture of litmus are added to a solution of 

 nitrate of potash so as to render it blue, and afterwards concentrated 

 sulphuric acid, the tincture is merely reddened by the sulphuric acid, 

 and by the nitric acid set free, but it is not at all decolorated. A 

 solution of chlorate of potash, on the contrary, which has been ren- 

 dered blue by tincture of litmus, is entirely decolorated by the 

 addition of concentrated sulphuric acid, a result by which the chlo- 

 rate is effectually distinguished from the nitrate. 



This effect is produced with the chlorate when one part is dis- 

 solved in sixty-four parts of water, but it ceases with eighty parts of 

 water ; but a solution of indigo is decolorated when water contains 

 only one-500th of its weight of chlorate of potash. 



This method of distinguishing the chlorates from the nitrates, 

 both in very dilute solutions, has besides the advantage of giving 

 certain results, in decolorating the tincture of litmus, even when the 

 chlorates are accompanied with chlorides and other salts. 



Tincture of litmus is not decolorated by a very weak solution of 

 nitrate of potash on the addition of sulphuric acid, even when some 

 hundredths of common salt or of other chlorides are present : it is 

 decolorated only when the nitrate of potash is dissolved in a con- 

 centrated solution of common salt. — Journ. de Pharm. et de Chim., 

 Mai 1842. 



ON THE EXISTENCE OF SULPHUR IN PLANTS. 

 M. Vogel, Sen., remarks, that it has been proved by the late M. 

 Planche and other chemists, that many plants contain sulphur. Wa- 



