TO RENDER FIREPROOF.
AS accidents, fatal and otherwise, are constantly happening, owing to clothing, curtains, portieres, window blinds, and the like catching fire, it may be useful to know that, if such articles are washed or soaked in a solution of ammonium chloride, they will be rendered absolutely fireproof. Woodwork and other inflammable material of any description, if similarlytreated, is likewise rendered either absolutely fireproof or, a tall events, very slow burning. This preparation used to be called (is even now sometimes called muriate of ammonia); that term, however, has almost entirely gone out of use. But in no case was it ever interchangeable or synonymous with ammonium nitrate—although that absurd mistake was recently made, and its correctness insisted upon by a contemporary, even after the ridiculous blunder had been pointed out and the ignorance of the writer thoroughly exposed. The formulas for the two are completely different. That for ammonium nitrate is as follows: NH4 + NO3; that for ammonium chloride is NH4Cl. If the former is subjected to heat it becomes N2O (laughing gas) +2H20 (water); whereas the ammonium chloride, if subjected to heat, sublimes over unchanged and thereby fireproofs the article which has been washed or steeped in it.