EARLY LITERATURE 169 



allowed to stand a year after a previous treatment for extraction of the 

 substance, iron ore in lakes in several places, flakes of metallic silver in 

 old pit timbers in certain mines — in fact, in Joachimthal silver has been 

 seen to grow out of the stones of the mine — 



"in the manner and fashion of grass, as from a root in the length of a finger, 

 very pleasant to behold. In places this silver doth embrace the stone in most 

 tender leaves, plates, and spangles. It sometimes beareth the shape of hairs; 

 sometimes of little twigs. Sometimes it beareth the shape of a tree." 



And so we pass on naturally to the "golden tree," to which frequent 

 reference is made by ancient writers and which is described by Peter 

 Martyr in the following terms : 



"They have found by experience that the vein of gold is a living tree, and 

 that the same by all ways spreadeth and springeth from the root, by the soft 

 pores and passages of the earth, putteth forth branches, even to the upper- 

 most part of the earth, and ceaseth not until it discover itself unto the open 

 air; at which time it showeth forth certain beautiful colors in the stead of 

 flowers, round stones of golden earth in the stead of fruits, and thin plates in 

 stead of leaves. These are they which are dispersed throughout the whole 

 island [he is speaking of Hispaniola] by the course of the rivers, eruptions of 

 the springs out of the mountains, and violent falls of the floods; for they 

 think such grains are not engendered where they are gathered, especially on 

 the dry land, but otherwise in the rivers. They say that the root of the 

 golden tree extendeth to the center of the earth, and there taketh nourishment 

 of increase ; for the deeper that they dig they find the trunks thereof to be so 

 much the greater, as far as they may follow it, for abundance of water spring- 

 ing in the mountains. Of the branches of this tree they find some as small as 

 a thread and others as big as a man's finger, according to the largeness or 

 straightness of the rifts and clefts. They have sometimes chanced on whole 

 caves, sustained and born up, as it were, with golden pillars, and this in the 

 ways by which the branches ascend : the which being filled with the substance 

 of the trunk creeping from beneath the branch, maketh itself way by which 

 it may pass out. It is oftentimes divided by encountering with some kind of 

 hard stone; yet it is in other clifts nourished by the exhalations and virtue 

 of the root." 



Modern" experimental Methods 



Thus we have in an antique dress the modern "theory of ascension," 

 as applied to the origin of mineral veins, and of the now well known fact 

 of the derivation of placer deposits from auriferous veins. 



In the years which have passed since the childhood of geological science 

 such a thorough knowledge of the structure, of at least the superficial 

 portion of the earth's crust, has been obtained that geological science in 

 many fields has developed that power of prediction which by some has 

 been cited as tlie cliaracteristic of a true science — so much so that the 



