6 THE "lEON BLOW' AT THE LINDA GOLDFIELD. 



enormous cliscliarge of volcanic and metalliferous as well as 

 mineral matter. The specimens consisted of a finely divided 

 poivder, mobile and soft to the touch, hrownish grey in colour. 

 Under the microscope, the following minerals could be 

 distinguished in the granules and spicules, viz.: quartz, two 

 felspars (one Avhite and one pink), augite, magnetite (strongly 

 magnetic, and scales of deej^ red specular iron oxide. After 

 subjecting this ash to several experimental tests, it was, as a 

 preliminary, found to possess a specific gravity of 2'64 at 18° 

 C, as compared Avith water at tlie same temperature. An 

 analysis of tlie material taken, as a whole, i,e., without any 

 previous mechanical separation of its constituent minerals, 

 and without previous digestion with water or acid, but dried up 

 100 C, gave no less than sixteen separate ingredients,, 

 amongst which were traces of silver. That metal was 

 su.bsequently obtained by icet assay; and it was also after- 

 wards found that it could be obtained from the ash by furnace 

 assay — fitsion with pure lead carbonate, sodium carbonate 

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

 so obtained or produced, which gave a minute bead of 

 metallic silver ; the same reagents were tested in larger 

 quantities, leaving out the ash, when negative results followed. 

 It was subsequently ascertained that silver could b'e extracted 

 from this volcanic ash by boiling it with a solution of 

 ammonia, or of potass, cyanide, or of sodium sulphate." 



The discovery of silver in the asla or mud, adds, for the 

 first time, this metal to the list of elementary substances 

 observed in the materials ejected from volcanoes, and the 

 addition derived some special interest from the fact of this 

 ash having come from the greatest volcanic (active) vents of 

 that great "argentiferous" zone of the Andes. Small as 

 would be the proportion of silver, it must represent a very 

 large quantity of that metal ejected during the eruption, in 

 view of the vast masses of volcanic ash, etc., distributed over 

 the large area which is indicated by the fall of argentiferous 

 ashes at a distance of 102 miles from the central crater to 

 Bahia de Caraguez. 



There cannot be, it is submitted, much difference of opinion 

 that, if silver, lead, iron, manganese, titanium, chlorium, 

 mercury and other less important metals occur in volcanic 

 ash or mud shown by frequent analyses, as derived, 

 inter alia from the immensely rich argentiferous formations 

 which that gigantic " vent " cotopaxi protrudes ; a similar 

 occurrence here on a smaller scale, within a well-known 

 *' auriferous zone " is not only feasible, but can be, or is now, 

 demonstrated to be a fact. The only, and to us most valuable 

 difference, is, that the South America ejecta expelled the 

 silver in its ashes, whilst, witli our " Iron Blow " the ash or 



