622 



NOMENCLATURE AND NOTATION, CHEMICAL. 



treatises and usage of a new set of names for a 

 large class of chemical compounds perhaps to 

 be ultimately extended to all compounds, or- 

 ganic as well as inorganic and names which, 

 it appears, were regarded as obviating some of 

 the difficulties and inconsistencies of the nomen- 

 clature hitherto in use, at least in text-books 

 in the English language. The system of names 

 proposed is, in fact, not wholly new, being in 

 good degree the same with that employed in 

 Gmelin's Hand-Book, and to some extent also 

 by Berzelius and other continental chemists. 

 Professor Williamson admitted the hopelessness 

 of changing the common usage as to the com- 

 mercial names of various substances, as soda, 

 arsenic, etc. ; but he considered a scientific sys- 

 tem of nomenclature as unsuited to ordinary 

 commercial use. Professor Odling called at- 

 tention to the impropriety of the use of the 

 word of, in the existing nomenclature, and 

 which the new system would escape : thus, to 

 call the compound CIO an oxide of chlorine, or 

 a chloride of oxygen, does not in either case 

 truly express the relation which in it the ele- 

 ments bear to each other. 



The following examples will illustrate both 

 the new notation, and the proposed new no- 

 menclature. Thus, among elements and com- 

 pound radicals : 



Free molecules of elements, as of Cl., O., N., 

 P., As, Hg, Cd, Zn, are thus represented : 

 CU, O 2 , N,, P 4 , As,, Hg, Cd, Zn; 

 and those of compound radicals thus : 



(CH,),, (CN) S , (NH 4 ),, NH 3 , C 2 H 4 . 

 The following examples illustrate symbols of 

 the molecules of bases, and the proposed names : 



H 2 0, hydric oxide (water) ; 

 K 2 0, potassic oxide (potash) ; 

 Cu 2 0, cuprous oxide ; 

 Cu 0, cupric oxide ; 

 (NH 4 ) 3 0, ammonic oxide ; 

 Bi a 3 , bismuthic oxide ; 

 Fe a 3 , ferric oxide ; 

 K ...S, potassic sulphide ; 

 (C,II 5 ) a O, ethylic oxide (ether) ; 

 C a H 4 0, ethylenic oxide ; 



the following, in like manner, in case of 

 molecules of acids : 



N U 3 , nitrous acid ; 

 N^Oj, nitric acid ; 

 I..,0 A , iodic acid ; 

 In0 7 , periodic acid ; 

 CO Z , carbonic acid ; 

 Si0 2 , silicic acid (silica); 

 Bo ,0 3 , boric acid ; 

 (C,H 3 0),0, acetic acid; 

 C 4 H 4 3 , succinic acid; 



and finally, these, in case of the molecules of salts : 



HN0 3 , hydric nitrate (monohydrated nitric acid) ; 



Fe(N0 3 ) 2 , ferrous nitrate ; 



Fe 2 (N0 3 J g , ferric nitrate; 



Fe 2 (S0 4 ) 3 , ferric sulphate; 



H 2 S0 4 , hydric sulphate (monohydrated sulphuric 



acid) ; 



HKS0 4 , hydro-potassic sulphate ; 

 H 3 P0 4 , hydric phosphate (trihydrated phosphoric 



acid) ; 



A1 2 C1 , aluminic chloride ; 

 HC1, hydric chloride (chlorhydric acid) ; 

 FeCl 3 , ferrous chloride ; 

 PtCl 4 , platinic chloride. 



The names assigned to compound bodies in 

 the author's recent work, Chemistry for Stu- 

 dents, are substantially in accordance with the 

 examples here given. Prof. W. A. Miller and 

 Mr. Newlands, while approving in substance 

 the proposed nomenclature, both insist on the 

 importance, with a view to definiteness and 

 fixedness in the employment of the names for 

 given compounds, not less than to accuracy in 

 their use as analytic and suggestive of chemical 

 composition, of incorporating with them as re- 

 quired the familiar prefixes, proto, di or M, tri, 

 tetra, sesqui, etc.; and the latter especially 

 would guard against assigning to compounds 

 analogous in composition differently formed 

 names. 



In the discussions above referred to, Pro- 

 fessors Graham, Odling, Brodie, Hofmann, 

 Miller, Frankland, and others took part. Prof. 

 Brodie expressed the opinion that chemistry 

 had reached a stage in which names of the now 

 usual forms may be abolished altogether, the 

 compounds being written or described merely 

 by the symbols which make up their formulas ; 

 but Prof. Frankland insisted that there must 

 still be, as now, the two systems of express- 

 ions. 



Prof. Williamson condemned Gerhardt's ap- 

 plication of the term acid to the hydrated acids. 

 He wonld restrict the term to what are now 

 called the anhydrous acids, or anhydrides, call- 

 ing the bare compound S0 3 sulphuric acid, etc. ; 

 while bodies of the former class he would re- 

 gard as hydrogen salts (see examples of salts, 

 above). These views, however, did not meet 

 with general approval. Prof. Miller has pro- 

 posed to substitute for the awkward expression 

 anhydride, the term oxyl. 



Finally, it may be remarked that the period 

 of transition in chemical theory and nomencla- 

 ture is not altogether passed. And at the best, 

 this transitional period has been, and while it 

 lasts must be, one of perplexity to both learners 

 and instructors. Hofmann states that he had 

 found such phrases as " old style," " new style," 

 "newest style," "little equivalents," "big 

 equivalents," etc., coming into use in instruc- 

 tion. The difficulties of such a transition, 

 however, are held to be trifling in comparison 

 with the advantages to be attained through its 

 consummation; among these being the scour- 

 ing in a higher degree than before of simplicity 

 and precision, both in theory and statement, 

 with greater practical utility, and an increased 

 value in the way of suggestiveness in the new 



