HYGIENIC NOTES. 39 



in the first place that miasmatic poison is most powerful between 

 sunset and sunrise' — more exactly, from the damp of the 

 evening until night vapors are dissipated ; we may be out in 

 the daytime with comparative impunity where to pass a night 

 would be almost certain disease. If forced to camp out, seek 

 the highest and dryest spot, put a good fire on the swamp side, 

 and also, if possible, let trees intervene. Never go out on an 

 empty stomach ; just a cup of coffee and a crust may make a 

 decided difference. Meet the earliest unfavorable symptoms 

 with quinine — I should rather say, if unacclimated, antici- 

 pate them with this invaluable agent. Endeavor to maintain 

 high health of all functions by the natural means of regularity 

 and temperance in diet, exercise and repose. " Taking cold :" 

 This vague "household word" indicates one or more of a long 

 varied train of unpleasant affections, nearly always traceable 

 to one or the other of only two causes : sudden change of tem- 

 perature, and unequal distribution of temperature. No ex- 

 tremes of heat or cold can alone effect this result ; persons 

 frozen to death do not "take cold" during the process. But 

 if a part of the body be rapidly cooled, as by evaporation from 

 a wet article of clothing, or by sitting in a draught of air, the 

 rest of the body remaining at an ordinary temperature ; or if 

 the tenaperature of the whole be suddenly changed by going out 

 into the cold, or, especially, by coming into a warm room, there 

 is much liability of trouble. There is an old saying — "when 

 the air comes fhrough a hole say your prayers to save your 

 soul ;" and I should think almost any one could get a "cold" 

 with a spoonful of water on the wrist held to a key-hole. Sin- 

 gular as it may seem, sudden warming when cold is more dan- 

 gerous than the reverse ; every one has noticed how soon the 

 haindkerchief is required on entering a heated room on a cold 

 day. Frost-bite is an extreme illustration of this. As the 

 Irishman said on picking himself up, it was not the fall, but 

 stopping so quickly, that hurt him ; it is not the lowering of 

 the temperature to the freezing point, but its subsequent ele- 

 vation, that devitalizes the tissue. This is why rubbing with 

 snow, or bathing in cold water, is required to restore safely a 



