358 NOMENCLATURE. . 237. 



that they are not meant to be systems of Natural History, 

 but something which indeed cannot always be defined or 

 reduced to clear ideas. 



The rest of the names need no further remarks. Some 

 of them belong entirely to the English idiom ; others have 

 long ago been introduced by mineralogical authors. The use 

 of these names is similar to that of the words explained be- 

 fore ; the ideas which they express being dependent upon 

 the contents of the orders to which they have been applied. 



The only two names newly introduced are Halolde and 

 Kerate. The first of these has been used by several che- 

 mists for certain compositions of Muriatic acid with other 

 bodies. The name, however, does not indicate this acid to 

 be contained in the mixture. It means only a substance 

 resembling salt, like octahedral Fluor-haloide, prismatoidal 

 Gypsum-haloide, rhombohedral Lime-haloide, &c. 



The above mentioned examples shew that there exist 

 mineral productions in nature, so very similar to the salts, 

 that is to say, to the minerals contained in the fourth order of 

 the first class, in respect to their natural-historical proper- 

 ties, that without a nearer examination, they might be 

 easily mistaken for one another ; and which, therefore, in- 

 deed possess that resemblance to salt in a remarkably high 

 degree. These substances form the first order of the se- 

 cond class, and have received the name of Haloides. 



Kerate is a translation of Horn-ore (to which Quicksilver 

 Horn-ore likewise belongs), suppressing only the word ore, 

 a name to which these substances are not entitled. In 

 Mineralogy, we find very often comparisons with horn, 

 sometimes not in a proper place, as in hornstone, horn- 

 blende, hornslate, &c. It may be tolerated in the Ke- 

 rates, though its application is not the consequence of its 

 particular merits. 



. 237, NAME OF THE GENUS. 



In the genus, the name of the order is more re- 

 stricted by connecting another word with the name 



