DISTINCTIVE CHARACTERS OF INFECTIOUS DISEASES. 9 



are all ushered in by a marked, and sometimes sudden, elevation 

 of bodily temperature, which, with variations, continues during 

 the course of the illness. It is because of this increased tempera- 

 ture that they are called fevers. Characteristic eruptions now 

 appear. Scarlatina on the second, measles on the fourth, and 

 smallpox on the third day, and so on. Now begins the infecting 

 period, which increases with the activity of the disease. 



SMALLPOX. The patient is now charging the air, and everything 

 about him, with a most subtle and deadly virus, derived chiefly 

 from the skin and mucous membranes, but not restricted to them. 

 There is no contagion so strong and sure, or that operates at so 

 great a distance, passing from house to house, from street to 

 street, making sanitary precautions difficult. I regret to add that 

 cases of this disease, imported from London, are already here. 



TYPHUS FEVER once contracted is highly infectious, and essen- 

 tially a disease of over-crowding and foul air from deficient 

 ventilation, associated with squalor and want, and a deteriorated 

 constitution from whatever cause. It chiefly infects by exhala- 

 tions from the skin and lungs. The patient's bedding and clothes 

 become saturated, and the poison clings so persistently to the 

 walls, and to everything in the room, as to make the destruction 

 of the latter in many cases necessary. 



TYPHOID FEVER differs from the preceding in its being but 

 slightly, if at all, infectious through the air. Here the seat of the 

 attack is the intestinal canal chiefly, and the poison is mainly 

 eliminated by that channel It is accordingly the intestinal 

 discharges, and clothes or bedding tainted with them, that have 

 to be mainly looked to, and every precaution taken by disinfec- 

 tion and removal, to prevent their access to water sources, such as 

 wells, or into house drains ; where, by decomposing, they infect by 

 their effluvia. These discharges acquire their maximum infective 

 power when decomposing. 



