8 EDITOR'S PEEFACE. 



But can the contents of these sewers not be made avail- 

 able ? The great mass of water which necessarily accom- 

 panies at present the fertilising matters, renders them of 

 comparatively little value when compared with the expense 

 of transport. But how to separate and concentrate these 

 matters from the water is a problem which is at present 

 occupying the earnest attention of scientific and practical 

 men. The solutions hitherto proposed are far from satis- 

 factory. The future of agriculture is, however, ultimately 

 connected with the right solution of this great sewage 

 question. 



In conclusion, I have only to state that the foreign 

 weights and measures have been, when necessary, trans- 

 lated into their equivalents in English, but have been left 

 unaltered when the point was only one of comparison, 

 which could be equally illustrated by the foreign weights. 



J. BLYTH, M. D. 



QUEEN'S COLLEGE, CORK : 

 March 16, 1863. 



