116 Selections. [No. 7, new series. 



storied building, is described as having occurred simultaneously 

 With this sinking of the brine, and it was believed that in 

 some of the deserted mines which honey-comb the rock-salt strata 

 of that region, the pillars of salt, which are always left to support 

 the roof, had been removed by the action of water, and the im- 

 mense weight of the superincumbent mass had then caused the 

 excavation to collapse. By an extensive disarrangement of this 

 nature, either some new channel of escape might have been open- 

 ed for the brine, or at least the communication between some of 

 the streams or reservoirs might have been closed or interrupted. 

 Similar occurrences, although with a converse effect, have happen- 

 ed in earlier times ; and two instances are mentioned by Holland, 

 in one of which, near Bickley, and also in the neighbourhood of 

 Combermere Abbey, the ground suddenly sank to a depth of many 

 feet, and the brine not being removed with the same rapidity as in 

 the present clay, forced its way to the surface upon its old subter- 

 ranean channel or reservoir being filled up, and formed a pool of 

 considerable size in the depression caused by the collapse of the 

 strata. 



The failure of 1856 appears to have been partial only, as would 

 be naturally expected if due to the alleged cause ; it seems to have 

 been almost wholly confined to the Northwich district ; at Wins- 

 ford it was slightly felt, but was there attributed more to increased 

 pumping than to any natural cause ; whilst in the Sandbach de- 

 partment I believe no complaint of any kind was raised. The de- 

 rangement, such as it was, seems to have been only temporary, for 

 no complaints have since been made of the occurrence of any 

 scarcity. 



On the Properties of Wood Oil. By M. Gtjibourt. 



An analysis of Wood-oil or Gurjim Balsam was made by Mr. 

 Charles Lowe* in 1850. He only knew it as a resinous liquid 

 extracted from an Indian tree and believed it to be balsam of 



* Pharm. Jour, Vol. xiv, 65. 



