Intelligence and Miscellaneous Articles. 73 



the farmer, the market-gardener, the planter or nurseryman, the grazier, 

 the sheep-master, to have before him such an approximation to the times 

 and order of their occurrence. 



• •**»** 



" There is a class of persons, however, to whom the paper may be imme- 

 diately acceptable, and possibly also useful in regulating their future plans. 

 The poor invalid may be soothed, and those of delicate constitutions en- 

 couraged, by the immediate prospect of a nine years' run of seasons having, 

 with little exception, the higher temperature of our climate. It may be the 

 means of inducing these to make trial at least of one or two of these, before 

 they resort to other skies more favoured by natural position, but extending 

 over countries far less desirable as residences to a truly British mind. And 

 medical gentlemen, when they have read and considered what is here laid 

 before them, may find arguments in it to strengthen such a conclusion." 



The work terminates with tables, showing the mean height of the 

 barometer, mean temperature, and depth of rain in each month, at 

 Ackworth, Yorkshire, through the cycle of eighteen years from 

 1824 to 1841. 



XIV. Intelligence and Miscellaneous Articles. 



ON THE RED MOLYBDATE OF LEAD. BY M. G. ROSE. 



IT is well known that the molybdate of lead from Retzbanya in the 

 Bannat is distinguished by its red colour from the other varieties, 

 and particularly from that which is found at Bleyberg in Carinthia ; 

 the crystallization of these two varieties is, however, the same. Prof. 

 Johnston lately made some researches to discover chromic acid in the 

 red crystals ; he submitted them to examination by the blow-pipe 

 and reported that they were entirely chromate of lead ; and he con- 

 cluded from this that chromate of lead is a dimorphous body. 



I brought with me from Siberia some red crystals of molybdate oi 

 lead, perfectly similar to those of Retzbanya, and I was able, not- 

 withstanding their extreme smallness, on account of the great bright- 

 ness of their faces, to measure the angles with the reflective gonio- 

 meter : their form is the haupto-octohedron of molybdate of lead, 

 slightly truncated on the superior edges. The inclination of the 

 faces, which by their intersection form their superior edges, is 99° 38', 

 and that of the lateral faces is 131° 55'. I also submitted these 

 small crystals to the action of the blow-pipe, and obtained results 

 different from those stated by Prof. Johnston. I was hence induced 

 to examine the crystals of Retzbanya, and I found that they behaved 

 with every test like the molybdate of lead of Bleyberg (Berzelius, 

 Trait6 du Chalumena, 3 e edition, § 252). There is only one exception 

 to this general statement : when fused with an excess of borax in the 

 exterior flame the red crystals yield a glass which becomes opake 

 on cooling, and has a slightly greenish colour, whilst the glass ob- 

 tained from the Bleyberg crystals is of a very pure white. 



The crystals of Retzbanya are easily decomposed in a mixture of 

 hydrochloric acid and alcohol ; a crystalline precipitate of chloride of 

 lead is formed, and the solution, which is greenish and transparent, 



