1867.] Mr. Jukes and the Geological Society. 329 



from wishing to discourage their use as measures of precaution. 

 More especially would I recommend filtration through animal 

 charcoal as a most undoubted and valuable means of greatly reducing 

 the amount of organic matter in water. I find that water will 

 readily pass through a stratum of animal charcoal three feet thick 

 at the rate of 41,472 gallons per day per square foot, the oxidizable 

 organic matter contained in the water being reduced to one half. 

 Five hundred tons of animal charcoal would be an ample quantity 

 through which thus to pass the whole of the present metropohtan 

 water supply. This at 13Z. per ton would cost 6,500/. The 

 charcoal would require to be heated to redness in retorts or ovens 

 for a couple of hours every six months. It would last for two 

 years and would then be worth nearly half its original cost as 

 manure. 



With regard to the excessive hardness of the London waters, it 

 does not appear that any practicable scheme of amelioration has yet 

 been contrived. Some years ago a beautiful and very simple process 

 of softening hard waters by the addition of lime was devised by 

 Dr. Clark of Aberdeen ; but although this process has repeatedly 

 been tried by water companies, it has invariably been again aban- 

 doned, since, notwithstanding the cheapness of the material employed, 

 the amount of carbonate of lime deposited by the London waters, 

 when submitted to this treatment, was, in the case of such vast 

 volumes of water, so enormous as to cause the process to be 

 pronounced impracticable. It is to be feared therefore that we must 

 for the present be content to block up the pores of our skins with 

 the greasy curd of hard water, but it is very desirable that the other 

 ameliorations of which I have spoken should be carried out at once, 

 although they ought not to delay the introduction of a water supply 

 free from sewage contamination, for until such a supply reaches the 

 metropolis its inhabitants will continue liable to repetitions of the 

 terrible slaughter which occurred last summer, from the effects of 

 which the east of London has not even yet recovered. 



II. ME. JUKES AND THE GEOLOGICAL SOCIETY.* 



It not unfrequently happens amongst large bodies of men whose 

 affairs are conducted by a committee, council, or directorate, that 

 the action of the executive will occasionally be disapproved of by 

 some one or more individuals, who may even feel personally injured 



* 'Additional Notes on the Grouping of the Eocks of North Devon and West 

 Somerset: with a Map and Section.' By J. Beete Jukes, M.A., F.E.S., &c. 

 Preceded by an Introductory Statement. Printed for circulation among the' 

 Fellows of the Geological Society of London. Dublin : Webb & Son, 1867, pp. 37. 



vol. rv. z 



