ON A NATURAL SYSTEM 



nre true names ; for although, from the power 

 of the words, they will apply to mnny Jubilan- 

 ces, nothing prevent* them from heing /!;*" 

 upplicd to the one or the other. In this way 

 ucidum ncrium was ufed in the. year 1772, for 

 aer fixum ; which is not abiblutely advancing a 

 falfehood, as it poflellcs a proper acid, and in 

 an aerial form ; but it is objectionable, becaulc 

 thcfe qualitiei arc diicoverablc in other fubftan- 

 ces. Let therefore fome other denomination be 

 fubflituted more exact and determinate, as, gas, 

 or acidum mcphiticum, or clfe there will be no 

 end to the various changes. But if it be iinpoiH- 

 ble to find one more accurate, it will be attend- 

 ed but with little inconvenience, to apply it to 

 that fubilance which we know for certain to be 

 the acidum aerium of the anticnts, 



r.i.xxxix, NwncjJ*gn{ffmg Icfs than (be Thing 

 defined fj tight to be a 



WHATEVER names exprcf* too 1 i mi ted a fen fe 

 fhould certainly be expunged, if a choice can be 

 made among thole that arc fynonijnous, ofpeci- 

 nlly thole recommended by long time; as they 

 convey fulfe and inadequate ideas. Thus mine- 

 ral indicates properly an ore ; but in the vul- 

 gar fenfe it fignifies every inorganic body found 

 in the bofom of the earth; although this idea is 

 more accurately expreiUrd by the word f'-JIU. 



In 



