A System of Instruction in the Practical Use of the Blowpipe - Being A Graduated Course Of Analysis For The Use Of Students And All Those Engaged In The Examination Of Metallic Combinations by Anonymous
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page 11 of 359 (03%)
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cannot very readily be mistaken for others. For this reason, reduction
is a very excellent expedient for the purpose of discerning and classifying many substances. B. UTENSILS. We shall give here a brief description of the most necessary apparatus used for analysis in the dry way, and of their use. _The Blowpipe_ is a small instrument, made generally out of brass, silver, or German silver, and was principally used in earlier times for the purpose of soldering small pieces of metals together. It is generally made in the form of a tube, bent at a right angle, but without a sharp corner. The largest one is about seven inches long, and the smallest about two inches. The latter one terminates with a small point, with a small orifice. The first use of the blowpipe that we have recorded is that of a Swedish mining officer, who used it in the year 1738 for chemical purposes, but we have the most meagre accounts of his operations. In 1758 another Swedish mining officer, by the name of Cronstedt, published his "Use of the Blowpipe in Chemistry and Mineralogy," translated into English, in 1770, by Van Engestroem. Bergman extended its use, and after him Ghan and the venerable Berzelius (1821). The blowpipe most generally used in chemical examinations is composed of the following parts: (_Fig._ 1.) A is a little reservoir made air-tight by grinding the part B into it. This reservoir serves the purpose of retaining the moisture with which the air from the mouth is charged. A small conical tube is fitted to this reservoir. This tube terminates in a fine orifice. As this small point is liable to get clogged up with soot, etc., it is better that |
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