128 PHILOSOPHICAL TRANSACTIONS, [aNNO 16q6-7 . 



lactuca sylv. costa spinosa, C. B. in July, many small drops or pearls of an oily 

 juire, coagulated and hardened like rosin, are plainly to be discerned, especially 

 with a single microscope: they are of an amber colour and transparent, easily 

 to be wiped of^'j'being only (^ily juice exuded: and probably even the blue flower 

 of ripe plumbs is nothing else but a fine resinous coagulation of the transuded 

 juice. On the underside of the leaves, and all over the stalk of bonus henricus, 

 J. B. stick infinite small transparent pearls: those clear drops are hard to the 

 touch, and feel like greasy sand, not clammy, and therefore it was well called 

 unctuous by C. B. 



And thus fur concerning the juices of plants, as they are difl^eretit, prin- 

 cipally by that accident of coagulation, and other natures. He next proceeds 

 to observations on the same juices of plants, as they are varied and distinguished 

 by that other accident, fermentation. And not only the juices of fruits are to 

 be wrought, or set a working, as of the apple, pear, briar, grape, &c. as is well 

 known ; but there is an artificial change, viz. inalting, to be made even in the 

 seeds of plants, so as to make them spend freely, or let go their juices, and 

 communicate them to common water, and receive a ferment : also the juice of 

 the roots glycyrrhiza will ferment, and the juice of the cane, as sugar. Again, 

 the tapped juices of vegetables are susceptible of a ferment. As for instance : 

 the 2 1 St of April ]665, about 8 in the morning, he bored a hole in the body 

 of a fair and large birch, and put in a cork with a quill in the middle ; after a 

 moment or two it began to drop, but yet very slowly: about 3 hours after it had 

 filled a pint glass, and then it dropped exceedingly fast, viz. every pulse a drop : 

 this liquor is not unpleasant to the taste, and not thick or troubled : yet it looks 

 as if some few drops of milk were spilt in a basin of fair water. There are 

 many ways of fermenting or setting this juice a woiking, that is, of keeping it 

 from coagulating. And here it may be observed what great change the juice, 

 particularly of this tree, undergoes, by being long buried under ground. Pimco 

 is one of the highest mountains in Craven, lying on the south side of that 

 country, about 2 miles above Carleton. On the south side the Pike, as they call 

 the verv top of that mountain, is a place where the water stands ; this is called 

 a moss, and is some fathoms perhaps deep in black mud. Here are dug up not 

 only roots, but whole trees, of fir, as they think; but upon due examination of 

 the grain and bark, Dr. Lister found them to be the roots of birch. Tiiese 

 roots split easily, and soon dry, and when dried, they burn with a lasting 

 flame ; and for this purpose they use them on any sudden occasion about their 

 houses: and although the flame be great, yet it is without any resinous smell. 

 However, it seems, that their having lain so long under ground, has prepared 

 the juice for burning. 



