The following is an abstract of a paper recently read before the Academy of Sciences, ! Paris, by A. Reynoso :— ; Geology has too often reason to take into ! consideration the results of the action of water upon substances imbeded at great depths in the earth, to render it necessary here to dwell upon the interest of all investigations o this nature. M. Alvaro Reynoso places the sut'sUuees which he desires to study in glass nbes, which are themselves enclosed in gunbanels. This little apparatus is plunged into an oil bath, which is heated to 536 or 572 Fab... taking the usual precautions against explosion. Water plays the part of a base in so many cases, that one cannot feel astonished, if, in the experiments that now occupy our attention, in which by the closure of the vessels it I becomes actually fixed, it should constitute an energetic base. Thus, for example, M. Reynoso has proved that quinine, which is converted into quinoline by potash under the ordinary pressure, undergoes precisely the ] same change by the mere action of water at about 482 Fah. j Phosphoric acid possesses the property of three very distinct classes of salts—the meta-1 phosphates, which are monobasic ; the pyro-phosphates, which are bibasic; and the phosphates, which are tribasic. When a meta-phosphate is heated with an excess of potash or soda, the acid is displaced or divided, and converted entirely into ordinary tribasic phosphate. Such is is also the action of water at 536 Fah. In the presence of a monobasic metaphosphate. it intervenes as a base, completing the constitution of an ordinary tribasic phosphate. The formula PO5, RO therefore becomes PO5, 3RO; but instead of a single salt of this form, there are produced thus— 6 (PO5 RO) -f-12HO= PO5,3RO +3PO5, RO- ! 2HO +2PO5,3HO In two of these salts, the fixed base and the water act the same part, the acid in the one being united to 3 atoms of base, in the other to 3 atoms of water . It is remarkable, that whilst the substances contain 6 ;'Jon of base, each capable of uniting with :; ii'Diins of acid, and, as it might be supposed, it'ttdy to seize upon it, the mineral base should only take 1 out of 6 atoms of acid leaving two to the water and dividing the other 3 with it. To judge from the result, one might be led to say. that at 536, Fah., water acts as a base with more energy than the mineral bases themselves. The pyrophosphates, which are bibasic, un- j dergo an analogous change, that is to say— j J(PO,2EO)=PO'"3RO +PO5, RO) 2HO) The water therefore unites with the mineral base in order to furnish the 6 atoms of base required for the formation of the two new salts. j It is clear that we should change nothing in the general expression of these tacts, if we said that the hydrogen of the water acts as a metal, instead of saying that the water acts as base. We shall not therefore stop to dilate upon this point of view. It must nevertheless be observed, that in such experiments the part played by the water does not always appear so simple ; more obscure affinities are sometimes manifested, which give rise to more numerous and complicated bodies. Thus— Bromide of cyanogen and water turnish hy-drobromate of ammonia and carbonic acid ; sulphocyanide of potassium gives bicarbonate of potash and hydrosulnhate ofsulphuret of ammonium; the cyanides of mercury and silver give. carbonate of ammonia and reduced metal. These reactions, which are frequently the last terms of a series of transformations of which the intermediate ones have disappeared, are very simply represented if we no longer regard water as a compound acting en masse, but as a source of oxygen and hydrogen, which can present either the one or the other in a nascent state. The formation of carbonic acid and ammonia in the presence of carbon and nitrogen is then no longer astonishing, and may be readily explained and foreseen.
This article was originally published with the title "Action of Water upon various Bodies at a High Temperature and under strong Pressure"