THE FIRE-DAMP'S FAMILY CIRCLE. 181 



numbers of the Philosophical Transactions (a series com- 

 menced, as is well known, in the year 1663) contain frequent 

 disquisitions upon it. 



The first precise account of damps in mineral veins I have 

 met with, is contained in a letter by Dr. Edward Brown, pub- 

 lished in the Philosophical Transactions for 1669. It is con- 

 cerning damps in the mines of Hungary, and their effects. 



Damps, the doctor was informed, occur in most of those 

 mines that are deep; they happen not only in cuniculi or 

 direct passages, but also in putei or perpendicular cuts or 

 descents. They are met with, he was informed, in ground 

 both soft and hard. A notable example of the latter occurred 

 in a copper-mine at Herngroundt (sic), where the ground was 

 so hard that cutting tools would not touch it, and which had 

 consequently to be blasted with gunpowder. 



Some damps, he tells us, suffocate ; others only cause faint- 

 ness. The doctor then proceeds to inform the reader, that 

 the German miners cure a damp by blowing it with a pair of 

 bellows, or by the insertion of a tube down upon it, and com- 

 municating with the air at the other extremity : methods 

 effectual enough, there can be little doubt, where the mining 

 excavations are inconsiderable. 'At Windschach,' says he, 

 ' they showed me a place where five miners and a gentleman 

 of quality were lost ; for which reason they have now placed a 

 tube there.' At Chremnitz they told the doctor that twenty- 

 eight men had been killed at one time in four cuniculi; 

 seven in each. Evidently the description given by the Hun- 

 garian miners to Dr. Brown refers to choke-damp, or an 

 accumulation of some kind of gas uncongenial to respiration, 

 most probably carbonic acid. As regards fire-damp, it was of 

 course out of the questian in the Hungarian mines adverted 

 to, as they were not coal-mines. 



At this time, when the theory and practice of ventilation 

 are so well understood, one seldom hears of damps except in 

 coal-mines, and of the choke-damp only as a consequence of 



