266 On the Definite Proportions in which the [April, 



Article III. 



Experiments to determine the Definite Proportioju, in which the 

 Elements of Organic Nature are comlined. By Jacob Berzclius, 

 M.D. F. K.S. Professor of Chemistry at Stockholm. 



III. Analysis of the Ternary Oxides. 



(Concluded from p. 184.) 



Substances not Acid. — I mentioned before that the ternary oxides 

 composed of carbon, hydrogen, and oxygen, have a strong ten- 

 dency to combine with saline bases ; and that in these combinations 

 they act the part of acids. They possess the acid characters, how- 

 ever, in very different degrees. iNIany of them possess the pro- 

 perty of combining at the same time with the strong acids, as is 

 the case with tannin, and almost all the extractive and colouring 

 matters. These oxides then are placed near the middle of the 

 electro-chemical chain, and their affinities diminish in proportion 

 as they approach the poirit of indiffereiice of that chain. The only 

 ternary oxide which contains nitricum, is a strong alkali; and the 

 quaternary oxides, which contain nitricum, have likewise properties 

 opposite to those of vegetable substances. They lie on the other 

 side of the point of indifference of the electro-chemical chain ; 

 their tendency to unite with acids being more distinct than to com- 

 bine with bases. 



The ternary oxides already analyzed are all of a decided electro- 

 negative character, so that chemistry gives them the name of acids; 

 if we except tannin, the acid properties of which are however very 

 distinct. 



It is known that the resins, fat oils, gums, extracts, &c., form 

 insoluble compounds with various metallic oxides. These combi- 

 nations are generally stated in such a manner in our Manuals of 

 Chemistry, that a reader, whose attention is not specially directed 

 towards these objects, considers these combinations as the only ones 

 of which these organic bodies are capable : and, in fact, they are 

 the only ones which are recognized by some striking property. 

 These insoluble combinations of ternary oxides with binary oxides 

 belonging to the class of salifiable bases, makes it probable that 

 there exists a general affinity between these ternary oxides and 

 bases. It is easy to convince ourselves of the truth of this suspicion 

 by experiment. 



Gum is precipitated by subacetate of lead, and sugar has the 

 property of rendering lime more soluble in v.ater. These facts 

 were ascertained without the consequence being drawn from them, 

 that these combinations owe tlicir existence to a general affinity ■ 

 between saline bases and vegetable bodies, in consequence of which 

 gum ought to have an affinity with, lime and sugar for oxide of lead. 



