1887.] On the Continuity of the Liquid and Gaseous States. 3 



afterwards found that the metal could be obtained from the ash by 

 furnace assay — fusion with pure lead carbonate, sodium carbonate, and 

 a little cream of tartar, and cupellation of the lead button produced ; 

 and a comparative experiment was made, with negative result, using 

 larger quantities of the same reagents, but omitting the volcanic ash. 



It was ascertained that silver could be extracted from the ash by 

 boiling it with a solution of ammonia, or of potassium cyanide, or of 

 sodiam thiosulphate, but the metal was not dissolved out in appreci- 

 able amount on boiling with nitric acid. Hence, as seems most 

 probable, it was present in the ash as silver chloride. The fact of 

 its being found in the solution in hydrochloric acid of the mass 

 resulting from fusion with the alkaline carbonates, is of course easily 

 explained by the solvent action upon silver chloride of the chlorides 

 of sodium and potassium, and (when such minute quantities are 

 concerned) of hydrochloric acid itself. 



The discovery of silver in the ash in question adds for the first time 

 this metal to the list of elementary substances observed in the 

 materials ejected from volcanoes, and the addition derives some special 

 interest from the fact of the ash having come from the greatest of the 

 volcanic vents of the great argentiferous chain of the Andes. 



Lead, which was found by Senor Santos himself, when a student 

 here in 1879, in a specimen of ash from the eruption of Cotopaxi of 

 August 23rd, 1878,* was sought for in the ash now reported upon, but 

 neither it nor any other heavy metal beside silver was detectable. 



Several concordant experiments proved that the silver was present 

 to the extent of about 1 part in 83,600 of the ash, or about two-fifths 

 of a Troy ounce per ton of 2240 pounds. Small as is this proportion, 

 it must represent a very large quantity of silver ejected during the 

 eruption, in view of the vast masses of volcanic ash which must have 

 been spread over such an area as is indicated by the fall at so distant 

 a point as Bahia de Caraguez. 



II, " Preliminary Note on the Continuity of the Liquid and 

 Gaseous States of Matter." By William Bams ay, Ph.D., 

 and Sydney Young, D.Sc. Communicated by Prof. G. G. 

 Stokes, D.C.L., P.R.S. Received November 30, 1886. 



For several years past we have been engaged in an examination of 

 the behaviour of liquids and gases through wide ranges of tempera- 

 ture and pressure. The results of our experiments with ethyl 

 alcohol have recently been published in the ' Philosophical Transac- 

 tions;' those with acetic acid in the 'Journal (Transactions) of the 

 Chemical Society'; and the Royal Society have in their hands a 



* 'Chem. News,' Oct. 17, 1879 (vol. 40, p. 186). 



B 2 



