Intelligence and Miscellaneous Articles. 73 



quantity of water, and pass chlorine gas through it to peroxidize 

 the iron entirely ; then precipitate the liquor by arseniate of potash; 

 the precipitate is of a greenish white colour, and consists entirely of 

 arseniate of iron. After some hours filter the liquor and wash the 

 precipitate with a large quantity of boiling water ; drj' it and calcine 

 it strongly to obtain the oxide of iron ; evaporate tiie solution which 

 contains the arseniate of manganese almost to dryness, and add 

 water to it ; if there remain by accident any traces of arseniate 

 of iron it separates. Then filter and decompose the solution by 

 caustic potash, and the oxide of manganese when well washed is 

 then perfectly pure. — Journ. de Pkarm. Sept. 1826. 



ACETATES OF MERCURy, 



Tliis salt, according to the experiments of M. Garot, consists of 



Acetic acid 20-3 



Protoxide of mercury . . 79*7 



100 

 Its theoretic composition, supposing it to be a neutral salt, he 

 considers to be 



Acetic acid 19"59 



Protoxide of mercury . . 80'41 



foo 



The peracetate by experiment was found to consist of 



Acetic acid 33 



Peroxide of mercury . . 67 



100 

 And its theoretic composition is stated to be 



Acetic acid 32 



Peroxide of mercury . . 68 



loo 



Ibid. Sept. 1826. 



PYRMONr HEAVY SPAK. 



The lieavy spar of Pyrmont has lately been analysed by Brandes 

 and Gruner, with the following results : sp. gr. 3'94'2. 



Sulphate of bary tes 92-2 



Sulphate of strontian 3"0 



Sulphate of lime 0*5 



Water 2*4 



Oxide of iron, with a trace of manganese 0'2 

 Ferruginous silica and alumina . . . 0-8 



991 

 Another variety : 



Sulphate of barytes 93*9 



Sulphate of strontian 3'1 



Sulphate of lime 0*5 



Water ] 2-5 



100 



Schiveigger's Journal. 

 New Series. Vol. 1. No. 1. Jan. 1827. L dis- 



