38 Accident from compression of the Air, 



A very singular and inexplicable fact is, that iron, tin, antimony 

 and tellurium, will not, like other metals, decompose the peroxide of 

 hydrogen. The act appears still more obscure, when we consider, 

 that the decomposition is effected by the protoxides of iron and tin. 

 Perhaps those of antimony and tellurium would produce the same 

 effect. 



The phenomena quoted above, are not explicable on any other 

 known principles, than those which we have here adopted. Whether 

 our readers will consider the rationale sufficiently free from hypoth- 

 esis we cannot determine. To us, it has appeared more probable, 

 at each revisal. 



Art. hi. — Compression of the Air. — jln account of a remarkable ac- 

 cident which occurred in a mine of Bovey coal, in consequence of 

 the compression of the Air ; by the Inspector, Dr. Professor JVog- 

 gerath. (Jahrbuch der Chem. und Phys.) 



(Translated and communicated for this Journal.) 



In order to understand correctly, the following account of the ac- 

 cident which occurred at the pit of Turnick in the territory of Co- 

 logne, it is necessary to premise a few words concerning the subter- 

 raneous position of the coal pits, and the manner of working them, 

 which for some time has prevailed in this region. The coal business 

 is of great importance in this district, and several hundred workmen 

 -are employed in it. 



Some pretty high ridges of hills, which arise in the basaltic Godes- 

 berg, extend more than half a league from Bonn on the Rhine, to 

 the region of Bergheim on the road from Cologne towards Aachen, 

 where they end in a plain, constituting tlie main locality of the terna- 

 ry formation of Bovey coal. This coal is commonly covered with 

 layers of clay not very compact ; and over the clay to the surface of 

 the ground, is a deposit of coarse sand and rubbish washed from the 

 hills. Where this covering is tliick and strong, in order to obtain 

 the coal to advantage, the mining is performed by a process, or rather 

 a particular kind of excavation, which in our region is termed turn- 

 melbau.^ The parts of the tummelbau are shafts, passages, and 



* Tummel is a corruption of the Latin word tumulus ; bau here signifies mine, 

 though it may mean any work or building. Tummelbau is an excavation in the 

 form of an obtuse cone. In the Jahrbuch there is a plate, conveying a very clear 

 idea of the manner of excavating these mines. 



