356 On the Discovery of Fluoric Acid in the Condrodite. 



this active agent, even when largely diluted, it is necessary 

 to be very nniich on our guard, lest the corrosion go too far, 

 and attack the plain parts of the glass. 



In this manner, the rich and beautiful picture, represent- 

 ing the Oto Council, as delineated in the atlas, illustrating 

 the narrative of Major Long's expedition, was elegantly 

 etched in two minutes. 



We have, for a course of years, tried many experiments 

 upon the etching of glass, by the fluoric acid vapor, and 

 have usually succeeded more or less perfectly ; but we can 

 confidently recommend the pure diluted acid, as being en- 

 tirely superior, in energy, neatness, and ease of manage- 

 ment. Although the strong acid is violent and dangerous, 

 in the extreme, and should be by no means allowed to touch 

 the skin, either in the fluid or vaporous state, the diluted 

 acid maybe managed with ease and safety. Still, a pupil, 

 who incautiously dropped some of the latter upon his hand, 

 experienced inconvenience for six weeks — that period hav- 

 ing elapsed before the sore was healed. 



It is proper to remark, that whenever the acid was pour- 

 ed from the receiver, the latter was firmly grasped by tongs 

 of a peculiar construction, in order to avoid the danger of 

 having the liquid come in contact with the hand. 



INTELLIGENCE AND MISCELLANIES. 



I. Domestic. 



1. Vindication of BIr. Henry Seybert's claim to the dis- 

 covery of fluoric acid in the condrodite, (Maclureite of Mr. 

 Seybert, yellow mineral of Sparta, N. J.) 



Philadelphia, Feb. 25, 1B23. 



Sir, 



But for some erroneous statements in Mr.Nuttall's reply 

 to my letter of the 1 1th November, 1822,* our Controver- 

 sy might have terminated. I feel it, however, a duly to 



*See Journal of Science and Arts, Vol VI, p. 168, & seq. 



