288 Miscellaneous. 



Mr. W. W. Fisher, in a paper " On the Salinity of Waters from- 

 the Oolites" {Analyst, Feb., 1904), remarks that the study of these 

 waters leads to the general conclusion that the uncovered beds 

 of limestone yield calcareous waters of a hard character, while the 

 deep beds, and especially the beds covered by clay, yield saline 

 or alkaline supplies. In his opinion the alkalies are normal con- 

 stituents of the strata from which the waters are obtained. The 

 chemical argument appears absolutely destructive of the hypothesis 

 that the constituents are derived from the infiltration of sea-water. 

 The alkaline carbonates probably owe their origin to the deca}^ of 

 organic matter originally deposited in and with the rock material,. 

 part of which still remains, and from which the products of 

 decomposition have not been removed by the circulation of under- 

 ground waters. It is precisely in situations where there is littla 

 or no movement possible that saline waters are met with. 



" Notes on Mining in Ireland " are contributed by Mr. G. H. 

 Kinahan (Trans. Inst. Mining Engineers, 1904). He sums up what 

 is known of the iron, silver, copper, and tin ores, of gold, and 

 also of salt, steatite, fuller's earth, pyrophyllite, and molybdenite. 



Mr. D. a. MacAlister, in dealing with " A Cross-Section and some 

 notes on the Tin and Copper Deposits of Camborne " (Trans. Roy. 

 Geol. Soc. Cornwall, vol. xii), remarks that while all the lodes 

 produce both tin and copper ores, those in the killas yield mainly 

 copper, and those in the granite mainly tin. In the Camborne areas 

 the lodes are ore-bearing fissures in the vicinity of elvan dykes, 

 and they must be regarded as having been a later product of the 

 same magma as that which gave rise to the elvans. The lodes 

 indeed appear to be influenced in the direction of their underlie 

 by the elvans, and like them they appear to converge in depth. 

 The richest tin zone in a series of ore fissures bears a fairly definite 

 position with regard to the surface of the granite, being more or 

 less parallel to it, and bending with it. The lodes are not uniformlj'- 

 productive to the deepest points reached by mining. Generally 

 speaking, the conditions assisting the deposition of cassiterite from 

 its solutions were more favourable near the periphery of the granite 

 than those nearer their source, and solutions reaching the cooler 

 regions near the contact deposited the whole of that cassiterite which 

 they had managed to retain in the upward journey. The author 

 deals with the secondary enrichment of lodes that may accompany 

 denudation of the area, and this appears to especially affect the copper 

 ores. In conclusion he is hopeful that with modern engineering 

 methods there will be a revival in Cornish mining. 



Mr. T. V. Holmes calls attention to " Some Grey wethers at Grays 

 Thurrock, Essex" (Essex Naturalist, vol. xiii). They were met 

 with in the old Thames Valley drift, and were probably derived 

 from the Woolwich and Reading Beds. 



