112 



A DISCOURSE 



BOOK I. of the Description of the Western Isles of Scotland tells us, that, upon 

 "^"^'^^^ his own experience, a rod of Oak, of four, five, six, or eight inches 

 about, being twisted like a wyth, boiled in wort, well dried, and 

 kept in a little bundle of barley-straw, and then steeped again in wort, 

 causes it to ferment, and procures yeast. The rod should be cut before 

 mid-day, and is frequently used in this manner to furnish yeast, and, 

 being preserved, will serve, and produce the same effect many years 

 together; and, as the historian affirms, that he was showed a piece 

 of thick wyth which had been kept for making ale with for above twenty 

 years \ In the mean time, the leaves of Oaks abundantly congested 

 on snow, preserve it as well, for wine, as a deep pit, or the most artificial 

 refrigeratory. Nor must we pass by the sweet mildews, so much more 

 copiously found on this tree than any other, whence the industrious 

 bees gather such abundance of honey, as that, instead of carrying 

 it to their hives, they glut themselves to death : But, from this ill report, 

 hastily taken up by Euricius Cordus, our learned Mr. Ray has vindicated 

 this temperate and abstemious useful creature. Varro affirms they made 

 salt of Oak ashes, with which they sometimes seasoned meat, but more 

 frequently made use of it to sprinkle among, and fertilize their seed- 

 corn ; which minds me of a certain Oak, found buried somewhere 

 in Transylvania, near the salt-pits, that was entirely converted into 

 an hard salt when they came to examine it by cutting. This experiment, 

 if true, may possibly encourage some other attempts for the multiplying 

 of salt. Nor less strange is that which some report of a certain water, 

 somewhere in Hungary, which transmutes the leaves of this tree into 

 brass, and iron into copper. ' Of the galls is made trial of spaw water. 



^ It is a practice in some parts of this country to dry yeast upon cap-paper, placed 

 in a wicker basket, in order that the ale may filter through. A small portion of this dried 

 cake, beaten up with warm water and a little pot-ash, makes an extemporaneous ferment 

 for bread. 



^ Brass is a factitious metal, and never discovered in a natural state; so that what 

 Mr. Evelyn here says must be regarded as fabulous. With respect to what he mentions 

 of iron being converted into copper, there is the appearance of truth in the experiment. 

 In Ireland there is a spring, in which, if plates of iron are laid, they will be converted, 

 in a few weeks, into copper: But in this case there is a fallacy, and no real transmutation. 

 The particles of iron are corroded by the acid in the water, and the particles of the copper, 

 minutely suspended in the menstruum, are deposited in their place. In this manner 

 considerable quantities of copper are collected. 



