a94 Decompofttm tf the Jcld of Bora*^ 



fome ftnall pieces of a fat flippery fubflance, a, A confiderable quantity of loofe card* 

 was alfo precipitated, of a light brown colour. 



Expcr. LV. On throwing the floating pieces, a [Exper. LIV.),into a folution of cauftic' 

 .alkali, they diflblved ; the folution had a reddifh-brown colour. 



Exper. LVI. With the fame folution of cauftic alkali I covered the light brown earth of 

 Exper. LIV. As the folution changed its colour to areddiftj brown, the earth gTaduaiiy 

 became perfectly white. 



Exper. LVII. I'o obfervc the affinity of other acids to the fedative fait, I poured fix drams' 

 of nitrous acid upon two drams of the fait, with ten drams of the forementioned oxygenated 

 muriatic acid ; digeffed the mixture, and diftilled it, in twenty-four hours, with a gentle heat.- 

 Upon the fluid fwam a white compa<5l fubftance, and fome fmall particles of the feme kind lay 

 at the bottom, which however rofe on the application of heat, and fwam about witTi the refi. 



Exper. LVIII. to LXIII. I poured the whole diftillation back upon the fait, and, by 

 means of a digefting heat, again drew ofJ^ a fluid, which appeared covered with a thin fat 

 ikin. I then poured the fluid back, diftilled it again, and thus repeated the procefs three 

 times more. No phenomenon particularly remarkable appeared, except that the thin fat (kirt 

 grew. more inconfiderable, and at laft feemed almoft to variifh. 



Exper. LXI V. The fait feparated from the fluid by the gentle diftillation in Exper. LXIII.- 

 emitted now, by the force of additional heat, dark red vapours, as is ufual in ftrong nitrous 

 acid. When the diftillation was at an end, the retort was expofed to an open fire ; but,- 

 tjuring this operation, no black matter a;ppeared j nor was any coal feparated from t-he mafs,. 

 upon diflblving it in diftilled water*. 



Exptr. LXV. I now tried the efFeA of a mixture of foiir drams of ftrong vitriolic acid- 

 and twelve drams of the muriatic acid, repeating the ufual digeflion and diftillation fix times. 

 I will pafs over other circumftanCes, and only mention, that after the fixth diftillation of the" 

 fluid, a ftronger heat, and at length an open fire, was applied ; but hardly any fluid was pro-< 

 duced, though the fire was fo violent, that the whole mafs appeared to be melted dawn intc» 

 one uniform compaft fubftance. 



Exper. LXVl. The veflels having cooled, the mafs was of a li^t milk.y. colour through- 

 out, without the leaft mixture of brown or black, or any other indication of coal \. Being 

 ibme time expofed to the air,, it became moift, and for a long time attraifled much water,- 

 which I eaufed to run off. At laft it remained pretty dry ; but the, mafs feemed to hav^e di-> 

 minifhed, by at leaft one-fourth part; 



Here Twill ftop, for the prefent, in the defcription of my experiments, which fufKciently, 

 tend to provCv in a general way, the decorapofition of fedative fait, and. to fhow, sliat one of 



*Here the. nitrous aciil feemed to deflroy, and (safry off. the infiaiiimable matter, foorfef tJVatf it tould bc-» 

 Gome cojl^ as it had beforii occaiioned the oHy a6d fat fabftaDC^ to vaitifli, in th«':beg>nning,x>f this cxp^' 

 rlment. 



+ Perhaps here alfo the remark contained in the former note holds good : yet I am. rather of opinion, thaf 

 ?to'vilribtifta«d did not operate with fufllcicnt ftrength to ,'cparate the component parts, 



iir 



