THE BLOW-PIFE. 643 
combination existing, consists of two hnmired separate 
troughs of Porcelain, coiinected together in regular order, each 
being composed of ten doable plates, arranged in cells, and 
containing in each plate 33 square inches ; so that the whole 
numberof double plates is 2000 ,and the whole surface 1 28,000 
square Inches. This battery, when tlie cells are filled with 
sixty parts of water, mixed with one part of nitric acid, 
and one part of sulphuric acid, affords a series of brilliant 
and impressive effects. When pieces of charcoal, about an 
inch in length, and one- sixth of an inch in diameter, are 
brought near each other (within the thirtieth or fortietli paw 
of an inch) a bright spark is produced, and more than half 
the volume of the charcoal becomes ignited to whiteness ; 
and, by withdrawing the points from each other, a constant 
discharge takes place through the heati^d air, in a space eqttal 
at least to four incites, producing a most brilliant ascending 
arch of light, broad, and conical in form in the middle. 
When any substance is introduced into this arch, it instantly 
becomes ignited ; platina melts as readily in it as wax in the 
flame of a common candle ; quartz, the sapphire, magnesia, 
lime, all enter into fusion : fragments of diamond, and points 
of charcoal and plumbago, rapidly disappear, and seem to 
evaporate in it. Such are the decomposing powers of 
electricity, that not even insoluble compounds are capable 
of resisting tlielr energy : for glass, sulphate of baryta, fluor 
spar, &c. when moistened and placed in contact widi 
electrified surfaces from the voltaic apparatus, are slowly 
acted on, and the alkaline, earthy, or acid matter earned to 
tile poles in the commoa order. Not even the most solid 
aggregates, nor the firmest compounds, arc c.ipablc of resist- 
ing this mode of attack ; its operation is slow, but the results 
are certain ; and sooner or later, by means of it, bodies arc 
resolved into simpler forms of matter. 
THE BLOW-PIPE. 
By the blow-pipe every effect of the most violent heat of 
furnaces may be produced, by the flame of a candle or lamp, 
urged upon a small particle ol any substance. Ihis iiisiru- 
nieiit consists merely of a bras.s pipe about one-eighth ot an 
inch in diameter at one end, and the otlici tapering to a 
otiud'^ loss with a verv small ucrtoration for the wind 
