Miscellaneous * 
181 
was obliged so to dispose of it ; and that a philosophical instrument, 
the finest of the kind the world had yet seen, should have been so 
egregiously thrown away. 
The blow pipe, supplied with hydrogen and oxygen gasses., 
affords a degree of heat nearly equal to the best burning glass. 
Dr. Bollman, who has so ably discussed (but not exhausted) 
j the question of banks and paper money, has succeeded in manu- 
facturing Platina into bars, wire, spoons, and crucibles. I do not 
know his process, which he has a right to reserve for his own 
emolument. The common method is, to dissolve the platina in 
nitro-muriatic acid, to precipitate it with sal-ammoniac ; to redis- 
solve and reprecipitate this orange-coloured oxyd of platina j to 
put it when dry into a crucible without addition, unless, perhaps* 
i of lamp black. It is exposed to a strong heat till it becomes ag- 
glutinated in a spongy mass. This spungy mass while strongly 
heated, is pressed down with as much force as the crucible will 
' admit, and this is continued till the parts approximate. The 
mass is then taken out, and hammered gradually and gently, till 
it unites in an uniform mass, and is then rolled. This, I say, is 
the common method. 
Dr. Bollmaif’s platina, is of specific gravity 19,7 the same as 
gold. Mr. Cloud, of the mint, to whom we are indebted for much 
useful and curious knowledge on platina, and the methods of puri- 
fying it, has freed it from the iron, palladium, iridium, and rho- 
| dium, so that his specimen of jiure platina, is upwards of 21 spec. 
J grav. I give this notice with great satisfaction, in hopes, that 
j Dr. Bollman may benefit by it, as well as the public. He is en» 
| titled so to do. 
The same gentleman lias also succeeded, in a small way, in 
; purifying the pyroligneous acid, so as to make it a substitute for 
i distilled vinegar : a manufacture, attended, as 1 hear, with great 
j success in France. In England, the pyroligneous acid (the acid 
liquor poduced from wood by distillation) has long been applied in 
the large way, to the making of iron liquor, for the dyers and prin 
ters of London and Manchester, 
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