G ORGANIZED BODIES. [iNTROD. 



called sulphate of soda, this view supposes that the soda yields its 

 oxygen to the sulphuric acid, and that a compound is formed of 

 sulphuric acid, plus an additional equivalent of oxygen, which may 

 be represented by SO 4 , and has been called by Professor Daniell 

 oxysulphion. The compound radicle thus formed unites with the 

 metal sodium, and the resultant salt should be called oxysulphion 

 of sodium. This view, then, it is evident, would lead us to regard 

 Glauber's salts as a binary compound, instead of a ternary one under 

 the first theory ; just as chloride of sodium is a binary compound, 

 the compound radicle, oxysulphion, and the simple one, chlorine, 

 standing in the same relation to the metal sodium. 



This latter theory, of the binary constitution of salts hitherto 

 regarded as oxygen salts, is of great interest in reference to the 

 composition of organic substances, as will appear in a future para- 

 graph. It has been supported by Professor Graham, and, subse- 

 quently, by Professor Daniell, whose opinion has been grounded on 

 the phenomena of electrical decompositions. 



Organized bodies are capable of being resolved, by chemical 

 analysis, into the inorganic simple elements ; but the list of simple 

 substances which may be obtained from this source comprises only 

 about seventeen. 



Of the four widely-spread elements, oxygen, hydrogen, nitrogen, 

 and carbon, two, at least, will be found in every organic compound ; 

 hence, as Dr. Prout has suggested, these four may be conveniently 

 distinguished as the essential elements of organic matter. The 

 other simple substances are found in smaller quantities, and are 

 less extensively diffused ; these may be termed its incidental ele- 

 ments. They are sulphur, phosphorus, chlorine, sodium, potassium, 

 calcium, magnesium, silicon, aluminum, iron, manganese, iodine, 

 and bromine ; the last two are obtained almost exclusively from 

 marine plants and animals. 



Between these elementary substances, and the organized animal 

 or vegetable texture, there intervenes a class of compounds, called 

 proximate principles, or organic compounds, or organizable substances. 

 These may be obtained in the first stage of the chemical analysis 

 of various animal or vegetable tissues. From the organized struc- 

 ture, called muscle, for example, we obtain by analysis, first fibrine, 

 a proximate principle, which is its chief constituent ; and, subse- 

 quently, by the analysis of fibrine, we get the simple elements, 

 oxygen, hydrogen, carbon, nitrogen, and sulphur, in certain pro- 

 portions. On the other hand, by synthesis, the combination of 

 certain inorganic elements (which hitherto has been effected only in 



