2 INTR OD UCTION. 



In the chapter devoted to the subject, the action of dangerous agents, more 

 generally encountered, is discussed. 



In the consideration of the different diseases, causes, symptoms, treatment 

 aiid prognosis are each of recognized importance, and diagnosis if necessaiy 

 to discriminate from one of several diseases with which it has more or 

 less symptomatic phenomena in common. 



To dwell on pathological anatomy, or the.appearances in a morbid or dis- 

 eased state, must necessarily confuse the reader and reference excepting 

 m rare Instances is avoided. 



In the arrangement of diseases convenience is studied. Under general 

 diseases are considered all unclassified. 



It is implied that operative surgery is beyond the capacity of many, and 

 as an exhaustive treatise on the subject would prove of but little value, 

 only the simpler operations, and treatment in cases of emergency are con- 

 sidered. 



