1790- LITERARY INTELLIGENCER. 37 



" In a letter from Baron Born, dated the 28th of July, 

 " he mentions having fent me 'La defcriptidn du cabinet 

 '' de Mademoifelle de Raab.' The fecond volume will be 

 " printed in two or three weeks ; in' this laft volume you 

 " will find the defcription of the regulus of terra pordero- 

 *' yi, or barytes, of magnefian earth, and of the calcarious 

 " earth ; for all thefe hitherto accounted earths, are no- 

 " thing elfe but raetallic calces." 



The publication here mentioned has not yet, that I know, 

 reached this country j when it arrives, further intelligence 

 refpefting thefe fubftances (hall be communicated to our 

 readers. 



On psrmanently Elajiic Fluids. 



The difcoveries of Dr. Prieftly refpe6ting permanently 

 elaftic fluids, air.s or gases, as they are generally called, 

 has opened a wide field for experim.ental enquiries, and has 

 produced a great revolution in the ideas of philofophers re- 

 ipefting the original and component parts of bodies, and 

 given rife to a new language in chemiftry. This laft al- 

 teration originated in France, and difcovers much ingenui- 

 ty J but being liable to great objeclions, it has not been 

 implicitly adopted. Hitherto our philofophical chemifts 

 have been chietly employed in differencing thefe gases, and 

 in Ceparating them from each other j fo that they are now 

 become extremely numerous. The time is not yet arrived 

 for fimplifying this branch of fcience, and reducing this 

 chaos Into order. In the mean time, various intereiiing 

 difcoveries have owed their rife to the refearches concern- 

 ing thefe fluids. The art of aeroftation, vrhich made fo 

 much noife for fometime, wasthemofi confpicuous of thefe ; 

 but as it has not yet been found that any ufeful purpofe 

 can be eifefted by thefe aerial voyages, they are now no 

 longer attended to. The cylindrical lamp, though its prin- 

 ciple depends upon properties of common air that were 

 known of old times, yet owes its oi-igin to the enquiries re- 

 fpefting air that have come into fafliion of late years. The 

 art of engraving on glafs, by means of the fluor acid j 

 that of forrhing artificial fire-works in imitation of flowers, 

 and other brilliant objedls, by means of differently colour- 

 ed inflammable gases ; the art of whitening linen in a 

 fhort time by means of diphlogifticated muriatic acid j and 



