V 



A NEW CHEMICAL NOMENCLATURE.* 



BY S. D. TILLMAN, A. M., 



PROFESSOR OF TECHNOLOGY IX THE AMERICAN INSTITUTE 

 OF THE CITY OF NEW YORK. 



THE present seems very opportune for the introduction of a Nomenclature 

 which will more completely methodize the Science of Chemistry. By such aid, 

 students, who formerly deserted the study because they found themselves gra- 

 dually sinking into a quagmire of incongruous names, may advance on firm 

 ground, and view with satisfaction and profit the fair fields opened on every 

 side by the distinguished chemists of our own time. The old nomenclature, 

 based on the joint production of DEMORVEAC, LAVOISIER, BERTHOLLET and 

 FOURCROY, published in 1787, has been frequently amended and enlarged ; yet, 

 to preserve the connection and consistency of the whole, names and classifica- 

 tions were retained long after they had lost their original significance. Even 

 the broad line of distinction between* acids and salts (made when oxygen acids 

 and neutral salts only were known), gradually diminished with the successive 

 discoveries of acid salts and the promulgation of new views by DAVY and DULONG, 

 until it is now no longer recognized by those who regard the whole class of 

 hydracids as true salts. A fatal error was committed at the outset, in attempt- 

 ing to define the acids containing most and least oxygen, by adopting 1 as ter- 

 minals (rendered into English) ic and ous, and the corresponding terminals 

 ate and ite for salts. Subsequent discoveries of higher and lower oxides in- 

 volved the necessity of using, as prefixes to the words in general use, the terms 

 hyper or per and hypo. Still these amendments have not obviated the difficulty, 

 as will be seen by reference to the combinations of oxygen with sulphur. This 

 conflict of terms was not, however, the greatest evil. The ic and ous terminals 

 are worse than useless for expressing the degrees of oxidation, because the 

 same terminal has a different signification in almost every series of oxides. 

 Similar objection may be made to the use of the terminal a in the names of 

 oxides; for example, Soda, now Na^O; Magnesia, MgO ; Alumina, AL0 3 ; and 

 Silica, formerly Si0 3 , by many now written Si0 2 . Early in the present century, 

 the words protoxide, deutoxide, etc. were used to distinguish the several de- 

 grees of oxidation having the simple ratio of combining proportions, i. f . 

 1:2, 1:3, 1:4. No more complex ratios than 2 : 3 were provided for. 



* Read at the meeting of the American Association for the Advancement of Science, held 

 in the city of Buffalo, Aug. 16th, 1866. 



165 



