Mineralogy and chemistry - John Lawrence Smith, Paperback

• Release Date   7/4/2012
• ISBN-13   9781236613547 | 978-1-236-61354-7
• ISBN   1236613546 | 1-236-61354-6
• Format   Paperback
• Author(s)   John Lawrence Smith
• This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1878 edition. Excerpt: ...It is then boiled for a short time in the same capsule, allowed to cool down a little, and then a concentrated solution of carbonate of ammonia is slowly added until there is an excess of the same. The solution becomes at first quite thick with the precipitate, but in a short time (especially with a little warming over the lamp) the precipitate accumulates in a more or less granular state, and afterward occupies less space in the filter than the alumina it might contain (in a feldspar, for instance) were this latter precipitated separately by ammonia. and this circumstance is of much importance in diminishing the length of the operations and the amount of water accumulated by filtering it from several precipitates. 21. It will be seen that thus far the operations have been carried on in the capsule in which the fusion was dissolved. The contents of the capsule are now thrown on a filter. but before doing this it is well to pour on a little of the solution of the carbonate of ammonia, and see if the clear part of the liquid be rendered turbid. in other words, ascertain if sufficient carbonate of ammonia had been originally added. 22. The solution that passes through the filter contains much sal ammoniac, the alkalies of the mineral, and a little lime. If magnesia be one of the ingredients of the silicate examined, some of this is also present. and in still rarer instances some of the earths soluble in carbonate of ammonia. This latter complicates in no degree the remaining steps in the analysis. It is best to let the filtrate pass into a glass flask. The washings of the filter are collected in another vessel and concentrated to a small bulk, added to the first filtrate, and the whole boiled for some time to drive off the carbonate of ammonia. When...