146 CALCAREOUS MANURES-PRACTICE. 



by far the most important. The paving of streets, (with any material,) 

 draining and filling up wet places, substituting for rotting wooden buildings 

 new ones of brick and stone— and especially the operation of destructive 

 and extensive fires— all, we know, operate (and particularly the last) to im- 

 prove the healthiness of towns ; and all these operated at Mobile, as well 

 as shelling the streets. Neither was the shelling so ordered as to produce 

 its best effect for health. The streets, alleys, and many yards and small 

 vacant lots were covered, and so far the formation and evolving of pesti- 

 lential effluvia were lessened. But as this was not the object in view, and 

 indeed the chemical action of shells was not thought of, the process was in- 

 complete, and must necessarily have been less eflfectual than it might have 

 been made. The shelling ought to have been extended to every open spot 

 where filth could accumulate — to every back yard, in every cellar, and 

 made the material of the floor of every stable, and every other building of 

 which the floor would otherwise be of common earth. In addition, after 

 a sufficient lapse of time to saturate with putrescent matters the upper part 

 of the calcareous layer, and thus to make it a very rich compound, there 

 should have been a partial or total removal of the mass, and a new coating 

 of shells laid down. The value of the old material, as manure, would pro- 

 bably go far towards paying for this renewal. If it is not so renewed, the 

 calcareous matter cannot combine with more than a certain amount of pu- 

 trescent matters ; and, after being so saturated, can have no further effect 

 in saving such matters for use, or preventing them from having their usual 

 evil course. 



The burning of towns is well known to be a cause of the healthiness of 

 the places being greatly improved, and that such effect continues after as 

 many buildings, or more, have replaced those destroyed by fire. Indeed 

 this improvement is considered so permanent, as well as considerable, that 

 the most sweeping and destructive conflagrations of some of our southern 

 towns have been afterwards acknowledged to have proved a gain and a 

 blessing. The principal and immediate mode of operation of this univer- 

 sally acknowledged cause is usually supposed to be the total destruction, 

 by the fire, of all filth and putrescent matters ; and in a less degree, and 

 more gradually, by afterwards substituting brick and stone for wooden 

 buildings, which are alv.^ays in a more or less decayed state. But though 

 these reasons have served heretofore to satisfy all, as to the beneficial con- 

 sequences of fires, surely they are altogether inadequate as causes for such 

 great and durable effects. The mere destruction of all putrescent matters 

 in a town, at any one time, would certainly leave a clear atmosphere, and 

 give strong assurance of health being improved for a short time afterwards. 

 But these matters would be replaced probably in the course of a few 

 months, by the residence of as many inhabitants, and the continuance of 

 the same general habits ; and most certainly this cause would lose all its 

 operation by the time the town was rebuilt. But there is one operation 

 produced by the burning of a town, which is far more powerful — which in 

 fact is indirectly the very practice which has been advocated — and the 

 effect of which, if given its due weight, furnishes proof of the theory set 

 forth, by the experience of every unhealthy town which has suffered much 

 from fire. If a fair eetimate is made of the immense quantity of mild calca- 

 reous earth M^hich is contained in the plastering and brick- work of even the 

 wooden dwelling-houses of a town, and still more of those built of ma- 

 sonry, it must be admitted that all that material being separated, broken 

 down, (soon or late,) and spread, by the burning of the houses and pulling 

 down their ruins, is enough to give a very heavy cover of calcareous earth 

 to the whole space of land burnt over. It is to this operation, in a far 



