Dr. Odling on Acids and Salts. 83 



Considering the relations of ammonia and phosphuretted hydrogen, 

 H 3 N and H 3 P respectively, and the relations of marsh-gas and sili- 

 ciuretted hydrogen, H 4 C and H 1 Si respectively, there should exist 

 nitrates and carbonates having the general formulae M 3 NO 4 and 

 M 4 C0 4 respectively, corresponding to ordinary phosphates and 

 silicates having the general formula? M s PO 4 and M 4 SiO 4 respec- 

 tively. It is observable, however, that in addition to ordinary 

 phosphates and silicates, there are other phosphates and silicates, 

 known respectively as metaphosphates and metasilicates, which differ 

 from the ordinary salts by the loss of an atom of base, and that it is 

 these metasalts to which ordinary nitrates and carbonates correspond, 

 thus : — 



Phosphate M 8 P0 4 -M a = MP0 3 Metaphosphate. 



MNO 3 Nitrate. 

 Silicate M 4 Si0 4 -iM a = M 2 Si0 3 Metasilicate. 



M 2 C0 3 Carbonate. 



But chemists are acquainted with a considerable number of car- 

 bonates and nitrates, which may be called orthocarbonates and ortho- 

 nitrates respectively, that do correspond in their formulae with 

 ordinary silicates and phosphates, as shown in the Table. 



Orthocarbonates. 



Ca 4 CO 4 Dicarbonate of calcium. 



Zn 4 CO 4 Dicarbonate of zinc. 



Mg 3 H CO 4 Dicarbonate of magnesium, 



Pb 4 CO 4 Dicarbonate of lead . 



Pb 3 HC0 4 White lead. 



Cu 4 C0 4 Mysorine. 



Cu 8 HC0 4 Azurite. 



Bi'" H CO 4 Dicarbonate of bismuth . 



Orthonitrates . 

 Pb 3 H NO 

 Pb 3 NO 



;i lead. 



Hg'HNO 4 / ^™^' 



Bi'"JN0 4 of bismuth. 

 The succeeding Tables present lists of the principal ter-oxygen 

 and tetra-oxygen mineral acids. Some of these acids are known 

 only through the medium of their metal- and ethyl-representatives. 



Ter- Oxygen Acids. 



Chloric H CI O 8 



Bromic H BrO 3 



Iodic H I O 3 



Nitric HNO 3 



Metaphosphoric H P O 3 



Sulphurous . . H a S O 3 



Selenious .... H a Se0 3 



Tellurous .... H a T s 



Carbonic .... H a C O 3 



Metasilicic. ... H a Si 0' 



G2 



Tetra- Oxygen Acids. 

 Perchloric .... H CI O 4 

 Periodic ....HI O 4 

 Permanganic . . H Mn 2 4 

 Sulphuric .... H 8 S O 4 

 Selenic .... H a Se O 4 

 Telluric . . . . H a T O 4 



Oxalic H a C a O 4 



Molybdic .... H a Mo 2 4 

 Vanadic .... H a V a O 4 

 Tungstic .... H 2 W 2 O 4 



