C si* 3 



by adding to it ad fafuritatem a clear folution of 

 an alcali, when the diflclved part will be precipi- 

 tated, and fall to the bottom. For this purpofe 

 the falfod<e (Sedt. xx.) may be very ufeful. 



SECT. LXT. 



The acid of nitre will fuffice for making expe- 

 riments upon ftones and earths ; but if the expe- 

 riments are to be extended to the metals, the other 

 two acids (Seel, lvii.) are alfo neceflary. As the 

 acids are very corrofive, they muft not be kept in 

 the ordinary Pocket-Laboratory, already delcribed, 

 for fear of fpoiling the other apparatus, if the 

 ftoppers fhould happen not to fit exactly to the 

 necks of the bottles, and fome of the acid fhould 

 be fplit. 



SECT. LXII. 



I have a feparate box, which is eight inches and 

 three quarters long, four inches broad, and five 

 inches high. In this box are three long and narrow 

 bottles, containing the acids, placed upright at 

 one end of it, two glafs matrafTes laid horizontally 

 in the upper part, and a little drawer underneath, 

 made on purpofe to fill the empty room below the 

 matrafTes, and to give the box a regular form ; 

 and as charcoal is not every where to be met with 

 in travelling, I always have a piece in this drawer 

 for the ufe of the Blow-pipe. 



SECT. LXIII. 



In order to keep the acids more clofe in the bot- 

 tles, fince the glafs-ftopper is not always fufficient, 

 1 have a glafs -cover betides, made fo, as to fcrew 



round 



