Production and Propagation of Malaria, 105 



sitlon, so is it the consequence of the exposure of the mud of 

 such receptacles of water ; a cause which is again treated of 

 at greater length in the subsequent chapter. 



This chapter relates to what the author calls obscure and 

 disputed cases. We shall pass over these, which, as not 

 implying precautionary measures, are of the least interest, 

 and commence by noticing the case of vegetable putrefaction. 

 It is attempted to show, tnat the vegetable need not be living 

 to produce malaria, but that, even if utterly decomposed, its 

 elements, acting on water, can generate this poison. Among 

 the cases under this head, are flax and hemp ponds, common 

 sewers and drains, dunghills, and tide harbours ; and the 

 evidences under each are sufficient to make good the asser- 

 tion. But the most important of all, in our view at least, 

 is bilge-water : since our author has pretty clearly shown that 

 all the fevers of ships (excepting, of course, a few casual in- 

 stances of contagion) arise from this cause, and that if ships 

 were kept clean, fever or sickness would be nearly unknown 

 at sea. This we do indeed conceive one of the most import- 

 ant points in the work before us ; and if the author has re- 

 ferred to Sir Henry Baynton, as a stranger, we can quote 

 him, as a friend, that warrants for all that is here asserted, 

 and for far more ; since his collection of facts on this subject 

 is most important, and we think him almost culpable in not 

 having long ago given them to the public. If the Leviathan 

 was always the healthiest ship in the navy ; if she even left 

 the West Indies, after a long anchorage and service, with a 

 crew of 500 men, and not one sick, it is a case in the navy 

 which never occurred before, nor since, and which arose 

 entirely from the knowledge of this able and careful officer 

 respecting the subject that we are discussing. 



A sixth chapter explains, under the head of revolutions in 

 the production of malaria, a variety of circumstances not 

 easily admitting of abridgment. The chief of these are, the 

 effects produced by drainages, and reversely, those which 

 arise from inundations or other incidental causes affecting 

 the state of the soil. But the most important view which it 

 contains is that which relates to the effect of embankment in 

 rivers, and to the geological changes produced by the distri- 

 bution of alluvia. As, however, we cannot well state this in 

 a small space, we shall pass to the chapter on the Propaga- 

 tion of Malaria. 



This is the largest, and, as it strikes us, the most interest- 

 ing of the whole ; while the author has made it the depo- 

 sitory of a variety of remarks and recommendations on this 



