The Development of the Periodic Law (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1896 edition. Excerpt: ...it is obvious that " Prout's law," or some modification of it, such as was many years ago suggested by Dumas, must be true, the atomic weights of all the other so-called elements must be multiples of that of hydrogen or multiples of that fraction of the hydrogen atom which may result from the dissociation of this body itself. If such fraction be very small as compared with the effect of the inevitable errors of experiment, the experimental vertification or refutation of the law will prove impossible, but if it be considerable, as, for instance, onehalf of the commonly known hydrogen atom, or onefourth as assumed by Dumas, the question admits of practical examination." The author further questioned the justice of the view taken by Stas of his results that 'Prout's law' is disproved by them or is not supported by them. "The careful work of Stas and others only proves by close agreement of the results that fortuitous errors have been reduced within narrow limits. It does not prove that all sources of constant error have been avoided and indeed this can never be absolutely proved, as we never can be sure that our knowledge of the substances we are dealing with is complete." He added that, of course, one distinct exception to the assumed law would disprove it, if that exception were itself fully proved, but this is not the case. "Out of the eighteen best known atomic weights ten approximate to integers within a range of variation less than one-tenth of a unit. The degree of probability that this is purely accidental is found to be only equal to 1: 1097.8. This seems to illustrate the point that not only is Prout's law not as yet absolutely over-turned, but that a heavy and...