CHEMICAL SCIENCE. 197 



half of which is placed in one of the outer compartments containing 

 iron, and the remainder in the other. The middle compartment, con- 

 taining the copper, is- filled with clean water up to the level of the salt 

 water in the two outer compartments. In orcler to prevent all access 

 of air, a cover is fitted to the decomposing vessel, and securely luted. 

 A bent tube to carry off the hydrogen gas, liberated in process of 

 decomposition of the water, is inserted in this cover, the end of the 

 tube being conducted into a vessel of water, to prevent any access of 

 air through the tube. The contents of the tank being continuously kept 

 at TO" to 150 Fah., the decomposition of the salt will be effected in 

 the course of seven days, when the two outer compartments will be 

 found to contain a solution of chloride of iron, and the middle compart- 

 ment a solution of caustic soda mixed with a small quantity of salt. 

 The strength of the soda solution will depend on the quantity of 

 water employed ; but if all the salt be decomposed, the solution will be 

 found to contain 1 ,327 pounds of dry caustic soda. 



IMPROVEMENT IN THE MANUFACTURE OP SOAP AND TURPENTINE. 



A PATENT has been granted to Mr. C. J. Meinicke, of New York, for 

 the manufacture of resin-soap and the purification of turpentine at 

 one operation. The process is, to take a thousand pounds of crude 

 turpentine and melt by steam, or otherwise, and add eight hundred 

 pounds of tallow, grease or fat. When both are in a perfect liquid 

 state, eight hundred parts of liquid soda, containing thirty per cent, of 

 dry soda, dissolved, is added and stirred up, the temperature of the 

 whole being increased at the same- time to 108. At this temperature 

 the soap is instantaneously formed ; the acids constituting the resin 

 of the turpentine, and those forming the grease being perfectly neu- 

 tralized by the alkali, and thus converted into liquid melted soap. 

 The essential oil of turpentine is set free at the same time, and, in 

 order to obtain the same, a solution of common salt is added, which 

 is necessary in the manufacture of all soap. The soap-kettle is then 

 connected with a condensing apparatus, usually employed by dis- 

 tillers of the spirits of turpentine, and then the temperature of 

 the whole is increased to the boiling point. The essential oil of tur- 

 pentine and the steam pass into the worm and are condensed. The 

 alkali sets the spirits of turpentine free, and in this manner two 

 articles of useful manufacture are produced with less expense for fuel 

 and labor. When all the essential oil is distilled over, the remaining 

 soap is finished in the common way now practised by all soap-makers. 

 Scientific American. 



IMPROVEMENT IN VULCANIZING INDIA-RUBBER. 



A PATENT has been granted to Mr. McCurdy for improvements in 

 vulcanizing india-rubber. In his specification he says : My experi- 

 ments have resulted in the discovery, that common commercial potash, 

 mixed with rubber, in proportion as small as two ounces of potash ^ to 

 16 ounces of rubber, when treated by mixing with the usual quantity 

 17* 



