OXYGEN SALTS OF METHYL. 823 



of anhydrous sulphuric acid and oxide of methyl condensed into 

 one volume, so that its combining measure is the same as that 

 of oxide of methyl or 4 volumes. It is decomposed very slowly 

 by cold water, but rapidly by hot water, the acid sulphate of 

 oxide of methyl and water being formed and oxide of methyl 

 liberated. This compound may be employed in preparing all 

 the other compounds of methyl, which are derived from it by 

 double decomposition. 



Acid sulphate of oxide of methyl, bisulphate of oxide of methyl, 

 sulphomethylic acid; HO. MeO + S 2 O 6 . This compound, dis- 

 covered at the same time by MM. Dumas and Peligot and by Dr. 

 Kane, is formed when concentrated sulphuric acid is mixed with 

 hydrate of oxide of methyl, and also on dissolving the neutral 

 sulphate in boiling water. Obtained by the last method and 

 concentrated by evaporation it is a colourless, syrupy, very acid 

 liquid which in dry air becomes a mass of white crystalline 

 needles. It combines with bases forming double salts, in which 

 the basic water of the acid is replaced by a metallic oxide. All 

 these salts are soluble in water. The double salt of oxide of 

 ammonium and oxide of ethyl has not yet been obtained. 



Sulphate of oxide of methyl and potash, MeO.KO,S 2 O 6 -f HO 

 crystallizes in rhomboidal tables, which have the lustre of 

 mother of pearl and deliquesce in damp air. Dr. Gregory has 

 obtained two double salts by dissolving the present salt in a satu- 

 rated solution of ferrocyanide of potassium, and evaporating ; 

 the first which crystallizes yellow and insoluble in alcohol, is 

 a compound of ferrocyanide of potassium and ferrocyanide 

 of methyl; the second a white salt soluble in alcohol is a 

 compound of sulphate of oxide of methyl and potash, bisul- 

 phate of potash and cyanide of methyl. 



Sulphate of oxide of methyl and barytes, MeO.KO,S 2 O 6 H- 

 2HO ; is prepared by mixing equal parts of concentrated sul- 

 phuric acid and hydrate of oxide of methyl, and heating the 

 mixture to its boiling point. After cooling, the liquid is diluted 

 and saturated first with carbonate of barytes and afterwards 

 with hydrate of barytes ; the excess of the latter is removed by 

 a stream of carbonic acid gas, and the liquid evaporated to its 

 crystallizing point by a gentle heat. The salt crystallizes in 

 colourless tables of a square base or in thin transparent plates, 

 which effloresce in air and may be made anhydrous in vacuo. 



Sulphate of oxide of methyl and lead, PbO.MeO,S 2 O 6 



