ANBWEK TO F. SEELHEIM'S KRMARES.
481
ANSWER'1'0 F. SEELAEIM'S REMARKS ON M Y FJ X P E R I M E N " ? ~ ON Cll I.ORINE.
BY VICTOR MEYER. Berichte der deutschea chemlschen Gesellschaft, 12.2201. Translated by H E N D S M A " .
Rased upon the well-known experiments o€ TrooRt and Hautefeuille, o n the behavior of platinum to chlorine a t high temperatures, as well as on observations of his own, F. Seelheim undertook to critically examine the experiments published b y C. Meyer and myself. H c assumes that in our experiments, the platinous chloride which had betw employed had volatilized, a n d that a mixture of two volumes of chlorine atid one roliiine of platinum gas had been the contents of our apparatup. This o b j w t i o ~ i is entirely without foundation. T h e chlorine was brought into the apparatus in the shape of platinous chloride, packed into small, deep, pail-shaped vessels. A t the end of each experiment, the contents of this vessel were always found as a compact rod of Hpongy platinum, fitting exactly into it, anti which frequently we were able t o extract from i t without injury to its Hhape. If earc W R R taken that the vessel with the sponge be removed from t h e appnr,ztuu R-ithout 1085, i t was found that the RTeight of the platiniim was alrnoht exactly the one required by theory as existing in plat'rious chloride. E o sublimation of platinum or forination of crystals could he observed. It is, therefore, evident that a volatilization of weighable quantities of platinum could not have taken place. Bnt even without taking into consideration these points of fact, thiq might, u priori, have been assumed, for if the platinous chloride be heated, the chlorine will be evolved as so011 as the temperature for its decomposition is reached, and will escape from the ceswl containing the platinum ; and, in the latter stages of the experiment, will be hardly in contact with it. Seelheim has evidently taken no notice of a remark at the c4ose of oui- paper, wherein it is stated that iodine, at high temperattires, undergoes exactly the same changes. Iodine, of course, was applied in its free Rtate, and not in the shape of a platiniim conipoand. T h e objections of Seelheim are, therefore, in this case, inapplicable. B u t if now chlorine and iodine in both cases show analogons beliavior, it is har lly t o be doubted that the observed facts muqt, in both caws, be explained as depending on the same cause. May I be allowed yet to say a few words regarding l'roost and Hautefeuille's curious discovery, which has been c*onfirmed by Seel-
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ABBTRACTB : AMERICAN CHEMICAL JOURNAL.
heim, that yellow-hot platinum, by an intermediate formation of platinic chloride,. may partly be volatilized, though platinous chloride is completely decomposed already a t a temperature M o w 600' C . I have frequently repeated Troost and tJauteferiille's experiment, and have investigated it likewise with regard to the quantitative proportions, and have found that in this, ab in others. where tbe quantity of the one or other is to he considered, time forms an important element. Of a certain quantity of platinum which, at 1570' ( ' , was acted upon by a lively current of dry chlorine gas, h i t one per rent. wah volatilized. From this it is evident M hy, i n our experiments, no perceptible quantities of platinum c~ouldbe I olatilizetl. F o r if the volatilized quantity of platinum is, within one hour, and i n a rapid current of chlorine gas, but one per cent., it i 5 widerit that, in otir case, within a few seconds, when t h e chlorine I \ inoleover not in motion, the volatilized quantity of platinum car) hardly amount to hundredths of this one per cent.-that i., a quantity which cannot b e weighed, as not Inore than 0.07 grm platinum ~ i i lJrewit. h ZLTU"EH,
Yovember, 1879 - ___
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Abstracts from American and Foreign Journals.
American Chemical Journal. Tlb?. Abstractor, J 'P
Itesearchen
r, x o .
4.
l%ATThHSHALl
PH D
the Complex Itiorynnic Acids, WOLCOTT term complex inorganic acids," is applied to those acids which are formed by the union of LWJ or more acids, with elimination of water, the product pobbessing properties like an acid containing a single radical. T h e author wfers t o the previous iiivestigations of Lauretit, Scheibler, Marignac and others, on the alkaline salt# nf tungstic acid, and remarks that t h e accurate study of these compounds presents peculiar difficnltiea, owing, principally, to t h e fact that the salts are frequently very complex in character-those of one series a1w often approaching those of another in composition-and that they are efflorescent, and are decomposed by boiling water. T h e tungstic oxide in the compounds referred t o was determined b y t h e method of Berzelius, niodifietl a5 follows : Mercurous nitrate is added in slight excess to the Iwiling solution of the tungstate, and mercuric oxide added until the inerciirous tungstate formed amumes a persistent reddish hue ; the precipitate is then strongly ignited. T h e water was determined b y simple ignition, and the alkaline bane wah generally eptitnated as difference.
GIBBS,M.D.-The
OIL
