182 OBSERVATIONS ON MURIATIC ACID. 



orange-coloured liquor, which 'has the fame fmell as the va- 



nu arid thu*dif- P ° Ur * This is the acid contained m tne ^ alt J and I ,iave P rovec * 

 engaged is not it to be hyperoxigenized muriatic acid. But, although the 

 P ure ' fait from which the acid is difengaged be pure, the acid itfelf 



is never fo ; becaufe the very ad of difengaging it effects its 

 decomposition, and fome of it is converted into oxigenized 

 muriatic acid. The colour of litmus paper, on this account, is 

 generally deftroyed by the liquor. I fay.on this account, be- 

 caufe I have fome reafon to believe, from having obferved this 

 not to be uniformly the cafe, that hyperoxigenized muriatic 

 acid reddens the vegetable blues. However, it mud be confi- 

 dered, that the fulphuric acid ufed to difengage the hyper- 

 oxigenized muriatic acid is dill prefent ; and we can draw no 

 certain conclufion, until we have obtained this acid free from 

 Heat produces a jj 0lher f u bftances. If to this mixture of hyperoxigenized 



violent and dan- . ' .. 



gerousexplofion.rnunate of potafh and fulphuric acid, heat be applied, an ex- 

 ceedingly violent explofion, with a white and vivid flafh, takes 

 place, before the liquor has attained the temperature of 125 

 of Fahrenheit. In order to obtain this acid, I attempted to 

 diftil 500 grains, in a glafs retort, in a water bath, with every 

 precaution againfr. fuch accidents as I could not but in fome 

 meafure expect ; when, almoft as foon as I had kindled the 

 fire, I fa w, in the bottom of the retort, an extremely white, 

 vivid, and rapid flafh, which was immediately followed by a 

 Narrative of an j ouc j re p 0r j- # The retort was reduced almoft to powder; fo 

 accident of this + ' \ r r- iii^ i • i i i 



nature. that lcarcely any fragments of it could be found in the labora- 



tory. The windows, and feveral glafs veffels, were broken. 

 I happened to be holding the neck of the retort, at the moment 

 of the explofion, yet received no injury, except a flight contu- 

 sion in the hand. But Dr. Vandier, a French gentleman of 

 confiderable chemical and medical talents, to whom I am in- 

 debted for much able affiftance in my laboratory, was wounded 

 in feveral places; particularly, the tunica conjunctiva of the 

 eye was fo lacerated, that a piece of it hung down, and, by 

 getting under the inferior eyelid, caufed the molt painful irri- 

 tation, and endangered his fight. One of the frontal arteries 

 alfo was divided. I relate thefe circumftances thus fully, as 

 the moll effectual means of putting upon their guard thofe who 

 Dilute acid ap- would repeat the experiment. If the fulphuric acid be dilute, 

 P ,ied * heat may be applied with more fafety ; and the phenomena 



are different. The hyperoxigenized muriatic acid is difen- 

 gaged 



