462 Intelligence and Miscellaneous Articles. 



A NEW METHOD OF SEPARATING MANGANESE FROM LIME AND 

 MAGNESIA. BY PROFESSOR STROMEYER. 



We are informed in a letter from Professor Stromeyer, that he has 

 found the following method successful in procuring the complete se- 

 paration of manganese from magnesia and lime. To an acid liquid 

 containing the peroxide of iron together with manganese, lime, and 

 magnesia, the carbonate of soda is added in the usual manner, so as 

 to precipitate the first, while the three latter oxides are held in solu- 

 tion by an excess of carbonic acid j and in order to prevent any man- 

 ganese from falling, the actual precipitation of the iron is effected by 

 the bicarbonate instead of the carbonate of soda. After acidulating 

 the filtered solution and concentrating it by evaporation, a current of 

 chlorine gas is transmitted through it. On neutralizing the free acid 

 by the gradual addition of bicarbonate of soda, the manganese sub- 

 sides in the form of the red oxide, being thus completely separated 

 from the magnesia and lime. — Brewster s Journal, April 1828. 



SINGULAR ACTION OF PHOSPHORIC ACID ON ALBUMEN. 



In his essays on the animal fluids Berzelius stated, that a solution 

 of albumen is not precipitated by phosphoric acid -, whereas Engel- 

 hart, in his interesting researches on the colouring matter of, the 

 blood, found that albumen is coagulated even in a dilute solution by 

 phosphoric acid. As Engelhart was at Stockholm last winter, he and 

 Berzelius inquired into the cause of difference in their statements, 

 and discovered that they were both right. A solution of phosphoric 

 acid, which had been kept some time in the laboratory, did not preci- 

 pitate a solution of albumen ; but phosphoric acid, recently prepared 

 either by the action of nitric acid on phosphorus or by direct combus- 

 tion, caused an abundant precipitate. On further examination, it 

 was found that phosphoric acid, recently ignited, always throws down 

 albumen j but that after being kept in solution for a few days, it 

 loses that property. The coagulating power is restored by heating 

 the acid to redness, but disappears again after the interval of a day. 



The cause of these phenomena is by no means apparent. It does 

 not depend on a higher degree of oxidation, for the change ensues in 

 close vessels equally as by exposure to the air. Perhaps, says Ber- 

 zelius, there may be some peculiar compound of water and the acid, 

 which is not formed at the moment of solution, and which has not 

 the property of precipitating albumen. — Annates de Chimieetde Phy- 

 sique, xxxv. 110. 



Remark on the preceding notice, by Dr. Turner. — On comparing 

 the facts observed by Berzelius and Dr. Engelhart, with the 

 formation of the pyrophosphate of soda, described by Mr. Clark in 

 the fourteenth Number of this Journal, it appeared probable that 

 phosphoric acid heated to redness may be converted into pyrophos- 

 phoric acid, or undergo that change which enables it to form a white 

 salt with silver. To put this supposition to the test of experiment, 

 some fragments of phosphorus were treated in a platinum crucible 



by 



