149 



lifeless organism. There are years in which this colossal chemical la- 

 boratory of decomposition does not cease its work for one, two, or three 

 months. 



The writer was contemporary with the marine forests, which, although 

 they had already entered upon their decline,' still resisted, through the 

 spontaneous compensation afforded by nature, the devastation of which 

 it had commenced to be the victim. He s iw the devastation in its 

 march, and now he does not meet with a sample of the useful tree in 

 places where formerly flourished an innumerable quantity of trees which 

 shaded vast sheets of mud. At the time when the marine forest existed, 

 the yellow fever had never shown itself in the city of Rio de Janeiro. 

 At all events, it is a coincidence to be noted. * 



The author of so many publications in the " Jornal do Commercio' 

 (Sr. Albuquerque) attributed yellow fever to the diffusion throughout 

 the atmosphere of acid of bromuret from the decomposition of marine 

 organisms ; and as I, since 1859, have become convinced that the bare- 

 ness of the mud banks, and consequent mortality among the Crustacea 

 mollusks, gives rise not only to the diffusion of that acid, but also to 

 other products more noxious for example, phosphorus disseminated on 

 a great scale, the terrible malady comes to us. W ill the symptons of poi- 

 soning by phosphorus in small quantities bear a perfect similitude to 

 icteroid typhus ? I shall limit myself to this question, which only com- 

 petent persons can answer in a positive manner. 



During the late hot season through which we have passed, at more 

 than one period, and during consecutive days, the tides were so weak 

 that even at their highest rise they did not cover the mud-banks. The 

 latter dried up immediately ; they cracked on the surface, and the whole 

 phenomena, already pointed out, followed. In the last months of 1882, 

 and especially in the beginning of 1883, the mortality of the shell-fish 

 was frightful, to which circumstance all the fishermen and other mari- 

 time labourers can bear testimony. On the shoals and banks where the 

 mussel had accumulated to the thickness of some centimetres, the de- 

 struction from the effect of the solar rays and the previous presence of 

 fresh water was complete. The 1 samanguias/ and other organisms ex- 

 isting on the surface of the uncovered shoals, had the same destiny. The 

 echinidi were totally destroyed, doubtless from the fresh water predomina- 

 ting over the salt in the Bay ; the latter being repelled by the prevalent 

 winds, could not enter the bar in a sufficient quantity to re-establish the 

 equilibrium or regain its empire. The residuum of the dead inhabi- 

 tants of the waters in the Bay, or the organic animal matter given up 

 to decomposition, would require to be reckoned at many thousands of 

 metrical tons. The withdrawing of the waters of the ocean was such in 

 the foregoing months that it became sensible even on the outside of the 

 bar. On the small islands and banks near the coast the extraordinary 

 mortality of the shell- fish, especially of mussels, produced exhalations so 

 repugaant as to provoke vomiting. 



In epidemic seasons of former years the same facts have occurred. 

 The fever has shown itself whenever the mass of organic matter already 

 in a state of putrefaction on the vast banks is greater. * 



It may be mere conjecture, but at all events it would be well to consider 

 all these matters which I pointed out, and investigate them, not only 

 in Rio de Janeiro, to the bay of which I limited my observation, but to 



