On the Alps <>/ Diutplduc, 165 



4. Water, v.liich contains less llian about an GOOOtli of salts in 

 solution, cannot be safely conducted in lead-pipes, without certain 

 precautions. 



5. Even this proportion will prove insufficient to prevent corro- 

 sion, unless a considerable part of the saline matter consist of carbo- 

 nates and sulphates, especially the former. 



6. So large a proportion as a 4000tli, probably even a consider- 

 ably larger proportion, will be insufficient, if the salts in solution be 

 in a great measure muriates. 



7. In all cases, even though the composition of the water seems 

 to bring it within the conditions of safety, now stated, an attentive 

 examination should be made of the water, after it has been running 

 for a few days through the pipes. For it is not improbable, that 

 other circumstances, besides those hitherto ascertained, may modify 

 the preventive influence of the neutral salts. 



8. Wlien the water is judged to be of a kind which is likely to 

 attack lead-pipes, or when it actually flows through them impreg- 

 nated with lead, a remedy may be found, either in leaving the pipes 

 full of the water, and at rest for three or four months, or by substi- 

 tuting for the water a weak solution of phosphate of soda, in tlio 

 proportion of about a 25,000ih part. 



Febniary 22.— The Right Hon. Lord Greenock, V. P., in 

 the Chair. 



I. On the Necessity of the Sense of Muscular Action to the 

 full E.vercise of the Organs of the Senses. By Sir 

 Charles Bell, K.H. 



March 7.— Sir T. M. Bnisu.\NE, Bart,, President, in the 

 Chair. 



1. On the most recent Disturbance of the Crust of the Earth, 



in respect to its suggesting a Hypothesis to account for 

 the Origin of Glaciers, By Sir George Mackenzie, Bart. 

 (Published in this Journal, vol. xxxiii. p. 1.) 



2. Geological Notes on the Alps of Dauphine. 13y Professor 



Forbes. 

 Tho <listrict proposc.1 to be dckcribed, in so far as it was &tu<licd 

 by the author in two journeys in 18ya and 1841, is an out-lycr or 



