j 4 6 A SYSTEM OF 



5. After being refined, it {hoots into irregular 

 figures : but the cryftals, which form them- 

 ielves after the firft operation, and are call- 

 ed Tincal, confiit of fiat octagonal prifms, 

 flat at the extremities, and with their an- 

 gles cut off or truncated *. 



* It is yet unknown of what fubflance the Eafl-Indians and 

 Chinefe prepare the borax. The unrefined, which is brought 

 to Europe under the name of t'mcal, looks like (oft foap, is 

 fat, and covers or encruds the borax criitals. The mine- 

 in after Mr. Swab, who has had an opporturity of making 

 experiments upon this tineal, has publifhed them in the A<ftf> 

 of the Royal Academy of Sciences at Stockholm for 1756. He 

 fays, that he has found in it a martial earth, and a fat fub- 

 flance, which, to fmell and other circumftances, comes neareft 

 to a mineral fat : as likewife, that pure borax does not yield 

 any hep&r fulphuris, when united with a phlogifton and a vi- 

 triolic acid* from which he concludes, that borax is prepared 

 from its own particular mineral fubllance. 



ProfefTor Pott and Mr. d'Henouville have very carefully 

 examined the refined borax ; and frcm their experiments, 

 which have been published, it is evident, that it is of a par- 

 ticular alcaline nature : however, there yet remains to know 

 for certain, from what it is prepared by the Indians : for, if 

 it is produced from a mineral fubflance, as is very probable, 

 there muft exift other mixtures and compofr.ions, which are 

 yet unknown to the learned world. 



I have alfo found in the timal fmall bits of leather, bones 

 and fmall pebbles, whence there is no certainty to be con- 

 cluded on from its examination ; but, if it fhould happen, 

 that it is prepared from animal fubftances, it muft be allowed, 

 that nature has formed an alcaline fait in the animal king- 

 dom, which anfwers to the fixed acid fa't in the human urine, 

 called fal fujibile microcofmicum, and which has been firfr. ac- 

 curately dcicribed by Mr. Margraif, in the Memoirs of the 

 Academy of Berlin. 



Some years ago a report was propagated from Saxony, that 

 fomebody had there di {covered a fubitance out of which borax 

 could be made, and alfo the art of preparing it : but nothing 

 more has ever tranfpired fmce, than that the author fhevved ic 

 in fecret to his friends, and gave a defcription of it, which 

 only was intended to miflead them, if he really did poifefs. 

 the art, 



SECT. 



