BOOK III.

49

A, B, C, D —The mountain. E, F, G, H, I, K — Vena cumulate.

SSaii

SHH

accumulations is usually formed a “ vena cumulata.”

‘ As to those that are found in underground canales which do not appear to have been derivedJ from the earth or rock adjoining, these have undoubtedly been carried by the water for agreater distance from their place of origin : which may be made clear to anyone who seeks“ their source.”

On the origin of solidified juices he states (De Ortu, p. 43): “ I will now speak of<( solidified juices ( sued concreti). I give this name to those minerals which are without(( difficulty resolved into liquids (humore). Some stones and metals, even though they areu themselves composed of juices, have been compressed so solidly by the cold that they can onlytt be dissolved with difficulty or not at all. . . . For juices, as I said above, are either

lt ma -de when dry substances immersed in moisture are cooked by heat, or else they arelt m ade when water flows over ‘ earth,’ or when the surrounding moisture corrodes metallic(t m aterial; or else they are forced out of the ground by the power of heat alone. There-f° re > solidified juices originate from liquid juices, which either heat or cold have condensed.„ But that which heat has dried, fire reduces to dust, and moisture dissolves. Not only„ d° es warm or cold water dissolve certain solidified juices, but also humid air; and a juice„ w hich the cold has condensed is liquefied by fire and warm water. A salty juice is con-,, ^f n sed into salt; a bitter one into soda ; an astringent and sharp one into alum or into„ vltr iol. Skilled workmen in a similar way to nature, evaporate water which contains„ i u ices of this kind until it is condensed; from salty ones they make salt, from„ aluminous ones alum, from one which contains vitriol they make vitriol. These workmen„ lm itate nature in condensing liquid juices with heat, but they cannot imitate nature in,, condensing them by cold. From an astringent juice not only is alum made and vitriol, but„ a ^ so sory, chalciiis, and misy, which appears to be the ‘ flower ’ of vitriol, just as melanteria„ ls sory. (See note on p. 573 for these minerals.) When humour corrodes pyrites so thatit is friable, an astringent juice of this kind is obtained.”

„ . On the Origin of Stones (De Ortu, p. 50), he states : “ It is now necessary to

„ revie w in a few words what I have said as to all of the material from which stones are„ ma de ; there is first of all mud ; next juice which is solidified by severe cold ; then frag-„ fuents of rock ; afterward stone juice (succus lapidescens), which also turns to stone when„ 1 comes out into the air; and lastly, everything which has pores capable of receiving a„ juice.” As to an “efficient force,” he states (p. 54) : “But it is now necessary

at I should explain my own view, omitting the first and antecedent causes. Thus the