288 ON THE NATURE AND HISTORY 



and having their point directed to a trifling concomitant cir- 

 cumstance of no importance. 



Should it be said, that the poison must then emanate from 

 aqueous putrefaction alone, I think this may be disproven by 

 equally familiar examples. The bilge-water in the holds of 

 ships, which at all times smells more offensively than the most 

 acknowledged pestiferous marshes, would in that case infallir 

 bly, and at all times, be generating fevers amongst the crew, 

 more particularly in tropical climates, I need scarcely say, 

 that this does not consist with the fact, unless it be in some 

 rare instances, where the bilge -water has become, like that of 

 the marsh, actually dried up, or absorbed into the collected 

 rubbish and foulness of the ship's well, thereby verifying the 

 common saying of the sailors, that a leaky ship is ever a heal- 

 thy ship, and vice versa. Or if it be objected, that the salt 

 may have a preserving power, let us look at the quantity of 

 fresh-water, (not unfrequently the impure water of an alluvial 

 river), laid in for a first-rate man of war proceeding on a long 

 voyage. This is so great as to constitute many floorings, or 

 tiers of barrels, close to which the people sleep with impunity, 

 though it is always disgustingly putrid, and could not fail to 

 affect them, if it contained any seeds of disease *. Examples of 

 the same on land may be found with equal facility. At Lis- 

 bon, 



* In some ships of our navy, the fresh-water, instead of being put up in casks, 

 has been preserved in bulk, by constructing a large open tank, of tin or lead, at . 

 the bottom of the hold, without in the least affecting the health of the crew, 

 though they slept immediately above it. On land, the very same results have 

 been verified under the same circumstances. One of the healUiiest officers'-quar- 

 ters in the West Indies, is the field-officers at Berkshire Hill, St Vincent's, which 

 is built immediately over the garrison water-tank ; and a block house at Deme- 

 rara, similarly situated, was healthier than the other posts on terra jirma. 



