IS 13.} Scientific Intelligence. GJ 



two, and Berzelius makes them four. Theory is certainly in fa- 

 vour of the hist opinion. The two oxides of antimony con- 

 taining most oxygen possess, according to Berzelius, the proper- 

 ties of acids. Ke calls them antimonious and antimonk acids. 

 The antimonious acid is white. The calx antimonii elota of the 

 old pharmacopoeias is this acid combined with potash, and con- 

 taining an excess of acid. When boiled in water a neutral 

 antimonite of potash is obtained, from which other antimonites 

 may be formed. The antimonite of barytes crystallizes in white 

 needles, and is not altered by exposure to the air. 



The antimonic acid has a straw yellow colour. It is formed 

 by heating antimony in nitro muriatic acid. Berzelius has ex- 

 amined several of the saline combinations which it forms with 

 the different bases. 



The two acids of antimony have the property of combining to- 

 gether, and of uniting likewise with the other oxides of that metal. 

 This makes it so difficult to examine the oxides of antimony with 

 accuracy. (See Berzelius, Larboh. i Kemien, ii. 159.) 



V. Acid of Tin. 



The peroxide of tin has been repeatedly considered as an acid 

 by chemists Bergman and Guyton Morveau have each pub- 

 lished dissertations on the subject. Berzelius has lately examined 

 the matter anew; and though he admits that it possesses some 

 characters in common with acids, yet he thinks that they are not 

 sufficient to entitle it to the name. 



VI. Acid of Tellurium. 



The oxide of tellurium, according to the observations of Ber- 

 telius, possesses at once the characters of an acid and a base. 

 Hence it u capable of combining with bases and forming salts, 

 while at the same time it unites with acids, and forms another 

 kind of saline compound. On that account we may either call 

 it telluric acid or oxide of tellurium. 



VII. Sulphate of Copper. 



It is well known to chemists that there are two oxides of 

 copper, the red and the black; the fiist composed of 1 atom of 

 metal and 1 atom of oxygen, the second of 1 atom of metal and 

 2 atoms of oxygen. The red oxide refuses to combine with 

 sulphuric acid. When the two substances are brought in con- 

 tact, the red jxide of copper divides itself into two equal por- 

 tions, one of which gives all its oxygen to the other; so that one 

 ■■If of the oxide is reduced to the metallic state, and one half 

 converted into black oxide. This last half unites with the 

 mlphttric acid, and forms common sulphate of copper. The 



