IV. TECHNICAL. 531 



These specimens show the various stages in the preparation of potash from 

 the mineral salts. 



Vorster and Gruneberg, Kalk b. Coin. 



Amyleue C 5 H 10 . [ Amylic Ether 



Amylhydride C S H 12 . I Triamylene 



Diamylene C 10 H2o. 



The preparations have all been manufactured from potato fusel oil (or Amylic 

 alcohol) according to a method which allows for the preparation of starch ; a 

 continuous and comparatively cheap process of production which can also be 

 carried out on a large scale. 



Julius Weinzierl, Gr. Glogau, Silesia. 



Phenoquinone C 1S H 14 O 4 . 

 Pyrogalloquinone C 18 H 14 O 8 

 Purpurogallin C 18 H 14 O 9 . 

 Triacetamide C 6 H 9 O 3 N. 



Bioxynaphtalene C 10 H 8 O 



Picric acid Bromonaphtalene 



C 6 H 2 (N0 2 ) 3 OHC 10 HyBr. 

 Binitronaphtalene C 10 H 6 N 2 O 4 . 



Bicyannaphtalene C 12 H 6 N 2 . 



Prof. Wichelhaus, Berlin. 



1. Bars of nickel; 2, bars of cobalt. These metal bars are about 170mm. 

 long and 42mm. broad and brightly polished. They form the first cast 

 pieces of cobalt and nickel of a large size which have ever been produced, 

 and date from the year 1866. W. Hankel made use of the same in his 

 investigations on the magnetic bearing of nickel and cobalt. (Berichte 

 der Konigl. Sachsischen Gesellschaft der Wissenschaften, mathematisch- 

 physische Klasse. Meeting of the 21st July 1875.) 



Prof. Winkler, Freiberg, Saxony. 



IV. TECHNICAL. 



2678. Digester, made of cast-steel, for digesting under 

 pressure. It holds 4 litres, is silvered inside and coppered outside. 

 Manufactured by Fr. Krupp, of Essen. 



Professor H. Landolt, Aix-la- Chapelle. 



2679. Chlorate of Potash. Muriate of potash containing about 

 90 per cent, chloride of potassium, and some impurities consisting 

 of chloride of sodium, sulphates of potash, soda, lime, and magnesia. 



James Muspratt fy Sons, Lancashire. 



2680. Chlorate of Potash. Milk of lime of about T08 

 specific gravity, made by well stirring up about 18 ctr. slacked 

 lime in about 6,800 litres water in a cast-iron vessel. The sample 

 contains a small quantity of chlorate and of chloride of calcium 

 from the previous solution made in the same vessel. 



James Muspratt fy Sons, Lancashire. 



2681. Chlorate of Potash. Solution of chlorate of lime of 

 about 1 15 specific gravity, containing at the same time chloride 



LI 2 



