﻿472 Royal Society : — 



water, illustrates the very great difficulty of manipulating with it and 

 retaining it in a pure state. Nevertheless, by the contrivances de- 

 scribed, and by placing the bottles in a cool cellar (never above a 

 temperature of 60° Fahr.), the author has succeeded in keeping the 

 liquid acid perfectly, without loss and unaltered, through the whole 

 of the recent hot summer. 



The electrical relations of different metals &c. in the acid were 

 found to be as follows at 0° Fahr. : — zinc, tin, lead, cadmium, in- 

 dium, magnesium, cobalt, aluminium, iron, nickel, bismuth, thallium, 

 copper, iridium, silver, gas- carbon, gold, platinum, palladium. 



Numerous experiments were made of electrolyzing the anhydrous 

 acid with anodes of gas-carbon, carbon of lignum -vitse and of many 

 other kinds of wood, of palladium, platinum, and gold. The gas- 

 carbon disintegrated rapidly ; all the kinds of charcoal flew to pieces 

 quickly ; and the anodes of palladium, platinum, and gold were cor- 

 roded without evolution of gas. The acid with a platinum anode con- 

 ducted electricity much more readily than pure water ; but with one 

 of gold it scarcely conducted at all. These electrolytic experiments 

 presented extreme difficulties, and were conducted in a platinum 

 apparatus (shown by a figure) specially devised for the purpose. 

 The particulars of the conditions and results obtained are described 

 in the paper. Various mixtures of the anhydrous acid with mono- 

 hydrated nitric acid, with sulphuric anhydride, and with monohy- 

 drated sulphuric acid were also electrolyzed by means of platinum 

 anodes, the particulars and results of which are also described. 



To obtain an idea of the general chemical behaviour of the pure 

 anhydrous acid, numerous substances (generally anhydrous) were 

 immersed in separate portions of the acid in platinum cups, kept at 

 a low temperature (0° to —20° Fahr.). The acid had scarcely any 

 effect upon any of the metalloids or noble metals ; and even the base 

 metals in a state of fine powder did not cause any evolution of hy- 

 drogen. Sodium and potassium behaved much the same as with 

 water. Nearly all the salts of the alkali and alkaline-earth metals 

 produced strong chemical action. Various anhydrides (specified) 

 dissolved freely. Strong aqueous hydrochloric acid produced active 

 effervescence. The alkalies and alkaline earths united strongly with 

 the acid. Peroxides gave no effect. Numerous oxides (specified) 

 produced strong chemical action, some of them dissolving. Some 

 nitrates were not chemically affected ; others (those of lead, barium, 

 and potassium) were decomposed. Fluorides generally were un- 

 changed ; but those of the alkali metals and of thallium produced 

 different degrees of chemical action, those of ammonium, rubidium, 

 and potassium uniting powerfully. Numerous chlorides were also 

 unaffected, whilst those of phosphorus (the solid one only), antimony 

 (the perchloride), titanium, and of the alkaline-earth and alkali me- 

 tals, were decomposed with strong action, and generally with effer- 

 vescence. The chlorates of potassium and sodium were also decom- 

 posed with evolution of chloric acid ; the bromides of the alkaline- 

 earth and alkali metals behaved like their chlorides. Bromate of 

 potassium rapidly set free bromine. Numerous iodides were unaf- 



