314 Scientific Intelligence, fre. 



Is it not much more philosophical as well as more convenient to 

 preserve always the same symbol for the same substance, instead of 

 returning to the old plan of circles, or the still more ridiculous form 

 of the marks of punctuation ? 



Proceeding, then, on the broad ground, that letters are to form 

 the basis of symbolical representation, and that these letters are 

 to be constantly adhered to, in order to preserve regularity ; if we 

 proceed to take a binary compound (to take the most simple form) 

 and consider it in order to express it symbolically, we find, that in 

 every binary compound, one of the elements is electro-negative, and 

 the other electro-positive ; and that it is the electro-negative element 

 which marks the substances with which this binary compound may 

 be capable of being combined. This peculiarity, therefore, seems to 

 indicate that the electro-negative element ought to form a prominent 

 part of the symbol. Would it not, therefore, be convenient to place 

 the symbol of the electro-negative element in smaller letters than, 

 and as an index to, the electro-positive one? Thus, to express pro- 

 toxide of iron, I would propose to write Fe , and to express chloride 

 of potassium K cl , and to express sulphuric acid S3°, making the 

 figure which is the co-efficient, or indicates the number of atoms of 

 the element, a little larger than the symbol for the element, accord- 

 ing to the plan already proposed by Mr. Hiley, (Records, ii. 478.) 

 In this manner, the composition, action and mode of combination of 

 the substance would constantly be kept in view, which is un- 

 doubtedly the great object of symbolic representation. The same 

 plan would also suit acids and bases with a compound electro-positive 

 element ; thus, for instance, acetic acid would have for its symbol 

 (4C 2 H) So, and tartaric acid, (4 C 2 H) 5o. 



Salts, or compounds of an acid and a base, are of course expressed 

 by uniting their formula;. As long as the salt is neutral, the com- 

 position may be expressed symbolically without difficulty. Thus, 

 the symbol for anhydrous sulphate of soda would be Na° S3°, and 

 for carbonate of lime Ca° C 20 ■ when, however, we are required to 

 express a salt with excess of acid or base, the case is different. A 

 figure must be placed in connexion with the acid or base as the case 

 may be, which will express the number of atoms of it which enter into 

 the compound. Now, this cannot be placed before the acid or base, 

 for this place may be occupied, as in the case of the yellow iodide of 

 mercury, or of claomel, the symbol for which according to Thomson's 

 view of their composition (which undoubtedly agrees with the atom 

 of mercury, as deduced from the specific gravity of its vapour, and 

 from its specific heat), would be 2 Hg 1 and 2 Hg cl respectively. 

 Nor can we place this figure as an index, according to the common 

 method, for the electro-negative element occupies that position more 

 advantageously. It is, however, equally convenient to place it above 

 the symbol of the acid or base. In this manner the symbol for 



bi-silicate of lime would be Ca° Si , and that for borax Na° B 1 ^ 

 + 8 H°. 



In still more intricate compounds, as when several salts are com- 

 bined together, as is not unfrequcntly the case in artificial compounds, 

 and very often in the mineral kingdom, it may be proper to intro- 



