ISBN: 9780217428774

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 illustra… Plus…

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. 1899. Excerpt: ... CHAPTER V ORIGIN AND DEVELOPMENT OF THE IDEAS OF VALENCY AND THE LINKING OF ATOMS It has already been explained in Chapter III. that the discovery by Dumas of the fact that chlorine may be introduced into organic compounds in exchange for hydrogen, equivalent for equivalent, led to very important changes in the then current ideas of chemical combination. Up to that time the electro-chemical theory of Berzelius had been almost entirely predominant, and, naturally, the notion that an electro-negative element like chlorine could be exchanged for an electro-positive element such as hydrogen, without fundamentally altering the characters of the resulting compound, was completely at variance with the canons of that theory. But facts remain, while theories must be left either to be adapted to the new state of knowledge, or to be abandoned altogether. In this case the theory has been modified, but even to the present day the interchange of negative chlorine and positive hydrogen is a phenomenon which still affords room for speculation. One important consequence of the establishment of the facts of substitution was the inception of the idea of types, a theory which, as remarked by Williamson many years later, was the vehicle of many an important discovery, and led to profound changes in the way of regarding chemical combination. A most instructive review of the whole position was given by Dumas himself in 1840.1 He then stated clearly that compounds which contain the. same number of equivalents united in the same manner, and which exhibit the same fundamental chemical properties, belong to the same chemical type. This view, though opposed by Berzelius, and at first by Liebig, was afterwards supported by the latter, who cited as analogous the case of chlorine and... Sir William Augustus Tilden, Books, History, A Short History of the Progress of Scientific Chemistry in Our Own Times Books>History, General Books LLC<

1680, ISBN: 9780217428774

[ED: Taschenbuch], [PU: Cambridge Scholars Publishing], Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. Th… Plus…

[ED: Taschenbuch], [PU: Cambridge Scholars Publishing], Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER II THE CHEMICAL ELEMENTS: THEIR DISTRIBUTION IN NATURE, AND RECOGNITION BY THE CHEMIST The word " element," apart from poetical usage, is now universally understood to mean a substance which, though it may pass through many transformations, is always recoverable undiminished in quantity from any chemical combination into which it may enter, and is not by any known means resolvable into two or more distinct kinds of matter. Sulphur, for example, is regarded as an element, notwithstanding the allotropic changes which it undergoes under the influence of heat, because from sulphur in any of its known forms nothing can be abstracted which is not sulphur in other words, it is homogeneous, and consists in its most minute parts of one kind of substance. On the other hand, water and iron rust are regarded as compounds because in proportion as, by suitable means, either of them is destroyed two kinds of new matter make their appearance, and the united weights of the products of "decomposition" are equal to the weight of the " compound" body from which they are educed. These ideas date from the time of RobertBoyle. In his "Sceptical Chymist" (1680), he demonstrated the inconsistencies not only of the ancient Aristotelian doctrine of the Four Elements, but showed how little of foundation in fact and how much of imagination was to be found in the alchemical doctrine of the Tria prima current in his day.1 Boyle not only insisted upon homogeneity as a characteristic of a true " element," but refused to admit any arguments but such as were based upon experiment. The materials of which the earth and its inhabitants consist are chiefly compound, but they are resolvable into a limited number of substances, regarded for the present as elementary, because they have never yet been dec...Versandfertig in 6-10 Tagen, [SC: 0.00]<

2012, ISBN: 0217428770

Paperback, [EAN: 9780217428774], General Books LLC, General Books LLC, Book, [PU: General Books LLC], 2012-01-31, General Books LLC, 65, History, 271237, Ancient History & Civilisation, 2… Plus…

Paperback, [EAN: 9780217428774], General Books LLC, General Books LLC, Book, [PU: General Books LLC], 2012-01-31, General Books LLC, 65, History, 271237, Ancient History & Civilisation, 276416, Archaeology, 271343, Britain & Ireland, 271480, Europe, 271565, North America, 271411, Military History, 772016, Maritime History, 771710, Political History, 772148, Social & Economic History, 772162, Cultural History, 771714, Religious History, 271389, Other Historical Subjects, 771724, Essays, Journals, Letters & True Accounts, 271605, Reference, 771718, World History, 771708, Countries & Regions, 4119251, Academic History, 1025612, Subjects, 266239, Books<

ISBN: 0217428770

[EAN: 9780217428774], Neubuch, Title: Short History of the Progress of Scientific Chemistry in Our / Author: William August Tilden / Paperback. New. This print-on-demand book ships from o… Plus…

[EAN: 9780217428774], Neubuch, Title: Short History of the Progress of Scientific Chemistry in Our / Author: William August Tilden / Paperback. New. This print-on-demand book ships from our central European warehouse in Germany within 7-10 working days by Airmail.<