428 Chronicles of Science. [Ji^ly, 



but which in consequence of neglect had, by the evaporation of the 

 liquor, become wrinkled up and dry. As a result of a series of 

 carefully-made experiments, he has proved undoubtedly the exist- 

 ence of fluorine in the brain. 



From some experiments made by Professor Bloxam, of King's 

 College, it appears that a mixture of tincture of guaiacum and 

 ozonized ether (that is to say, a solution of peroxide of hydrogen 

 in ether) instantly produces, with blood or bloodstains, a beautiful 

 blue tint. Professor Bloxam mentioned that in the case of a blood- 

 stain twenty years old, he had extracted a single linen fibre with 

 an almost inappreciable amount of stain on it ; and had found the 

 ^characteristic blue colour was immediately mduced by the test, and 

 readily detected by microscopical examination. 



It is a well-known fact that iron is dissolved by molten zinc, 

 but nowhere is any definite alloy of these metals described, nor yet 

 is it stated how much iron is dissolved by zinc. Dr. Oudemans, 

 jun., obtained for analysis a piece of alloy which had been formed 

 in an iron vessel wherein zinc had been fused for several weeks 

 continuously ; this alloy was found deposited at the bottom of the 

 vessel, and became an impediment to the melting operations, in 

 consequence of its relative infusibility. In its physical aspect the 

 alloy was of very much whiter colour, and crystalline structure 

 entirely difierent from zinc; the aUoy dissolved very readily and 

 briskly in dilute sulphuric or hydrochloric acid, and was found, on 

 analysis, to contain 4 • 6 per cent, of iron. 



M. Zschiesche has prepared sulphate of lanthanium of such 

 a purity that a thickness of 17 centimetres of a saturated solution 

 gave no trace of the absorption bands of didymium. Working on 

 this, he has found the atomic weight of lanthanium to be, from a 

 mean of six experiments, 45 • 09. The extremes were 44 * 72 and 

 45-625. 



M. E. Ludwig has come to the conclusion, as a consequence of 

 a series of determinations of the specific gravity of chlorme gas, 

 that this gas belongs to those vapours which only obey Mariotte's 

 law when it is at a temperature rather remote from that at which 

 it is condensed to the fluid state. The specific gravity of chlorine 

 at 20° C. is 2-4807; at 50° C, 2-4783; at 100", 2-4685; at 

 150°, 2-4609; at 200°, 2-4502. According to experiments made 

 by Stas, the specific gravity of chlorine, deduced from its atomic 

 weight, is 2-45012. 



In order to obtain a platmizing fluid capable of platinizing 

 copper, yellow metal, and brass, add, to a moderately-concentrated 

 solution of chloride of platinum, finely-powdered carbonate of soda 

 until efiervescence ceases, next some glucose, and afterwai'ds just 



