554 



Intelligence and Miscellaneous Articles. 



following Table, where the letters have the same meaning as in the 

 Table relative to chloride of calcium : — 



M. 



Ml 



T. 



T 

 M' 



T 

 Mi' 



1 





6-6 



0-600 





2 





1-2 



id. 





4 





2-4 



id. 





6 





3-6 



id. 





8 





4-8 



id. 





10 





60 



id. 





12 





7-2 



id. 





14 





8-4 



id. 





15 



27-04 



9-2 



0-613 



0-340 



16 



29-06 



9-9 



0-619 



0-341 



17 



31-07 



10-6 



0-623 



0-341 



18 



33 17 



11-4 



0-633 



0-343 



19 



35-29 



121 



0-637 



0-342 



20 



37-38 



12-8 



0-640 



0-342 



Lastly, the lowering of the freezing-point in the case of chloride 

 of barium is proportional to the quantity of salt crystallized with 

 two equivalents of water. The coefficient of proportionality is 

 0-192. — Proceedings of the Academy of Sciences at Berlin, April 1 861 . 



EXPERIMENTS ON SOME AMALGAMS. BY J. P. JOULE, LL.D. 



The weakness of the affinity which holds the constituents of amal- 

 gams in combination seemed to the author to offer the means of 

 studying the relationship between chemical and mechanical force. 

 His inquiries were extended to several amalgams, and gave results 

 of which the following is a summary. 



Amalgam of iron was formed by precipitating iron on mercury 

 electrolytically. The solid amalgam containing the largest quantity 

 of mercury appeared to be a binary compound. Iron does not appear 

 to lose any of its magnetic virtue in consequence of its combination 

 with mercury. Its amalgamation has the effect of making it nega- 

 tive with respect to iron in the electro- chemical series. The affinity 

 between mercury and iron is so feeble that the amalgam is speedily 

 decomposed when left undisturbed, and almost immediately when 

 agitated. The application of a pressure of fifty tons to the square 

 inch drives out so much mercury as to leave only 30 per cent, of it 

 in the resulting button. 



Amalgam, of Copper. — By precipitating copper on mercury electro- 

 lytically, a mass of crystals is gradually formed. After a certain 

 time the crystals begin to get fringed with pink, indicating uncom- 

 bined copper. In this state the amalgam is found to be nearly a 

 binary compound. On applying strong pressure to an amalgam con- 

 taining excess of mercury, the latter is driven off, leaving a hard 

 mass composed of equivalents of the metals. If, however, the pres- 



