XIV BY .T. THOJISOX, M.B. 



him. Again, the enemy may overcome the outposts and skir- 

 mishers, and an invasion, limited in its area and effects, may be 

 accomplished, the results Deing inflammation or suppuration, or 

 even local death of the part, but without septica'Uiia or blood 

 poisoning ; or the enemy may overspread and devastate, 

 occasionally, but not necessarily, working special local mischief. 

 The invading pathogenetic bacteria, as in the case of anthrax, 

 cholera, diphtheria, or other of the highly malignant and fatal 

 diseases, may rapidly proliferate, and in so doing alter the human 

 fluids and tissues in which they grow — 



1st — By the assimilation of nutritive material ; 



2nd — By the products of secretion, elaborated and given out 

 by the bacterial cell ; 



8rd — By subsequent secondary changes, induced by these 

 products. 



Bacteriological chemistry is still in its very earlie.st infancy, 

 and the " bacterial products " referred to are not worked out in 

 chemical equation, as in the cases of vinous and acetous fermen- 

 tation. s Here, complex nitrogenous or proteid coiiipounds are 

 being attacked, and vital forces are arranged on both sides, and 

 the result is a poison, " and, knowing as little as we do, it is 

 safest to apply to these bacterial poisons the general term — 

 to.vin." And yet to.iin.s vary ; in some diseases they seem to be 

 specific poisons, in others only the poison -producers. But how- 

 ever it be, bacteriology has taught the physician the cama 

 anis/(ns of many ailments, and he, in his turn, is devising anti- 

 .tu.rinn for their effectual cure. 



Saprogenetic or Putrefaction Producing. — I am sure you 

 will pairdon me if I quote the oft-quoted but graphic description, 

 by DucLAux, of putrefaction processes and effects: — 



" Whenever and wherever there is decomposition of organic 

 matter, whether it be the case of a herb or an oak, of a worm or 

 a whale, the work is exclusively done by infinitely small organ- 

 isms. They are the important, almost the only agents of 

 universal hygiene ; they clear away more quickly than the dogs 

 of Constantinople or the wild beasts of the desert, the remains 

 of all that has had life ; they protect the living against the dead ; 

 they do more : if there are still living beings, if. since the 

 hundreds of centuries the world has been inhabited, life con- 

 tinues, it is to them we owe it. Without them the surface of 

 the earth would be covered with dead organic matter, the 

 remains of plants and animal bodies, which retaining the ele- 

 ments necessary for the building up of new plant life and animal- 



