356 PHILOSOPHICAL TRANSACTIONS. [aNNO I669. 



have shot but branches near two feet long ; and from the top of the sets, which 

 were a yard high, the briars have also grown backwards from that part which 

 we left remaining to the roots at the lesser ends ; they have great leaves, and 

 are ready to flower. 



Extract of a Letter from Dr. Edward Browne to the Editor, concern- 

 ing Damps* in the Mines of Hungary and their Effects. Dated 

 Vienna, April 20, 166*9. N' 48, p, 965. 



Having been lately in the copper, silver, and gold mines in Hungary, I hope 

 ere long to give you a particular account of them ; presenting this in the mean 

 time concerning damps in these mines ; whereof I understand that they happen 

 in most of them that are deep ; and that they happen not only in the cuniculi 

 or direct passages, where they walk on horizontally (by these mine-men called 

 stollen) but also in the putei or perpendicular cuts or descents (termed schachts 

 by the same.) They are met with not only in places where the earth is full of 

 clay or the like substances, but also where it is rocky ; and one place they 

 showed me in the copper-mine at Herrngroundt, where there had been a very 

 pernicious damp, and yet the rock so hard, that it could not be broken by their 

 instruments ; but the descent was all made by the means of gunpowder, rammed 

 into long round holes in the rock, and so blown up. Another place they 

 showed me, where there is sometimes a damp, and sometimes clear weather. 

 When there is much water in the mine, so as to stop up the lower part of this 

 passage, then the damp becomes discoverable, and commonly strong. I pro- 

 cured one to enter it, till his lamp went out 4 or 5 times, in the same manner 

 as at Grotto del Cane in Italy. 



Damps are not all of the same force, but some weaker, some stronger ; some 

 suftbcate in a small space of time, others only render the workmen faint, with 

 no further hurt, unless they continue long in the place. The miners (who 

 think themselves no workmen, if they be not able to cure a damp, or to cure 

 the bad weather, or make the weather, as they term it) perform it by perflation, 

 by letting the air in and out, and causing as it were a circulation of it. In the 

 mine at Herrngroundt they cured a bad damp by a great pair of bellows, which 

 were blown continually for many days. The ordinary remedy is by long tubes, 

 through which the air continually passing, they are able to dig straight on for a 

 long way without impediment in breathing. For some cuniculi are 500 fathoms 

 long ; which will not seem strange to any one that shall see the map of the 



* What the so called damps in mines are we have already explained at p. \6, vol. i. of this 

 Abridgement. 



