The use of the blowpipe in the examination of minerals, ores, furnace-products, and other metallic combinations / By Professor Plattner ... Translated from the German, with emendations, by Dr. Seridan Muspratt ... With a preface by Professor Liebig.
- Karl Friedrich Plattner
- Date:
- 1845
Licence: Public Domain Mark
Credit: The use of the blowpipe in the examination of minerals, ores, furnace-products, and other metallic combinations / By Professor Plattner ... Translated from the German, with emendations, by Dr. Seridan Muspratt ... With a preface by Professor Liebig. Source: Wellcome Collection.
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![Plattner’s Scale—Its use in quantitative silver assayings. The examinations for silver described in the preceding pages, being effected from 1 decigramme, (a standard re- presenting the ecwt. in small operations,) Plattner constructed a scale in order to use it for metallic globules obtained from an assay of this weight. He triturated, there- fore, intimately, a quantity of ruby silver, with an equal quantity of a poor calcareous silver spar, and cupelled the mixture. He repeated this operation several times, and constantly found 122°5 loths, or 5°48 per cent. silver. He then submitted the assay to the blowpipe, and obtained the same re- sult. The annexed wood-engraving (Fig.48) ishis scale, divided into 50 parts, the first of which answers to the globule obtained from 1 deci- gramme of an ore containing 5°48 per cent.* The constant factor be is therefore equal to 0-00098 for the division in loths ; and = = 0'00004384, if the content be expressed decimally. It is evident that a scale so constructed might be greatly extended, in order to serve for measuring metallic globules of a far greater volume than what is indicated in the foregoing remarks. This, however, is in- convenient; as the weight of spheres varies directly as the cubes of their diameters, the differences of weight for each division of the scale increase considerably,—therefore, a button having a greater gravity than can be ascertained upon any scale, may readily be weighed upon the balance. *[ The prefixed Scales are only intended to enable the reader to comprehend the description more easily. ]](https://iiif.wellcomecollection.org/image/b29334810_0327.jp2/full/800%2C/0/default.jpg)
