PETER SPENCE 273 



added a mixed solution of sulphate of iron 

 and copper, by which sulphocyanide of copper 

 is produced, which being treated with a 

 solution of sulphide of ammonium the copper 

 was separated, and the sulphocyanide of 

 ammonium formed and obtained in crystals. 



In 1875 he took out in conjunction with 

 his son Frank his first patent for the treat- 

 ment of Bauxite and the production of 

 Alumino-ferric. These salts he found to be 

 of value in the purification of sewage, and 

 also in the purification of water; valuable also 

 in paper-making and dyeing, and the firm at 

 present makes a large quantity of this low- 

 priced aluminous compound. 



His last patent, taken out just a year before 

 he died, is the one unhappily associated with 

 the memorable law suit between A. G. Kurtz 

 and Co., of St. Helens, and his firm. The 

 invention is that in solutions of sulphate of 

 alumina, which contain iron, the iron is 

 precipitated by black oxide of manganese 

 being added to the liquor. 



The same tastes that induced Peter Spence, 

 as a youth, to be an active member of the 

 Debating Society, at Brechin, caused him to 

 take a lively interest in the proceedings of the 

 Manchester Literary and Philosophical Society. 



