DRAININGS. 



117 



must be employed (with the exception of gypsum) 

 in far larger quantities, are open to the objection, that 

 great masses of solid substances would speedily col- 

 lect in the reservoirs. Muriatic acid also could be 

 used, but the cheaper and more powerful sulphuric 

 acid is much to be preferred. 



Here also the opportunity must be taken of call- 

 ing attention to an important precautionary measure. 

 Sulphuric acid is notoriously a very burning and cor- 

 rosive fluid ; that is, it chars and destroys most ani- 

 mal and vegetable substances ; it has, moreover, the 

 property of uniting' with water, causing the evolution 

 of violent heat. Hence very severe burns may be 

 easily incurred, if any portion of this acid is attempt- 

 ed to be removed from the skin by the application of 

 a small quantity of water. For this reason, when it 

 comes into contact with the skin, the latter should 

 first be wiped dry with any soft substance (as paper 

 or cloth), and then be immediately washed with a 

 great quantity of water. 



3. The application of drain ings to dunghills or 

 heaps of compost must be also highly recommended, 

 since by this means they can be readily brought into 

 a very manageable form without sustaining a loss of 

 their fertilizing power. If in collecting these heaps 

 of compost all the refuse matters found upon a farm 

 (as ought to be the case) are made use of, whatever 

 their appellations (sweepings, rubbish, sawdust, ashes 

 of all sorts, soot, path trimmings, road-grit, turf or 

 coal dust, dish-water, soap-suds, blood, etc.), and the 



