396 MATER i A MEDIC A AND THERAPEUTICS. 



but only at its effects. Still even this limited power may be of 

 the greatest value ; sometimes it is all that is required we 

 may have to treat only the effect that persists after the cause has 

 ceased or been removed, especially in sensitive and vital organs. 

 This kind of treatment is called symptomatic, palliative, 

 and under certain circumstances expectant (expectare, to wait) ; 

 it is manifestly a copy of the third method of natural recovery. 



It is evident that we have before us here an enormous field 

 for research and application. If we can but find a means, 

 whether medicinal or not, which shall counteract each abnormal 

 condition to which the body may be subjected, we may defy 

 disease. But here we are met by certain difficulties. Before 

 we can hope to combat disease in this way, we must know (1) 

 all about disease and its causes, that is, we must have a perfect 

 pathology ; and (2) all about the effects of therapeutical agents 

 upon the body, that is, have a complete pharmacodynamics or 

 pharmacology. It is unnecessary to say how far either the 

 one or the other of these is from being a complete science. 

 Another discouraging fact is that there is a limit to all hope 

 of a cure, a limit to all treatment, because the morbid influence 

 may have so far anticipated the remedial as to have altered the 

 body structurally. If a limb is lost, we cannot restore it ; if the 

 mitral valve is covered with diseased growth, we cannot renovate 

 it. But we are right when we maintain that these organic 

 structural changes, grave or hopeless as they may be, are but 

 the results of the action of some cause with simple beginnings, 

 which we shall yet discover. As our knowledge of pathology 

 advances we are steadily learning, e.g. more about the nature and 

 origin of cancer, for which the limb had to be removed ; more 

 about the causes of rheumatism, which covered the cardiac valve 

 with unnatural growth. If we ever cure cancer and rheumatism, 

 we shall manifestly do so by influencing the causes or .the 

 beginnings of the two diseases : medicines may be expected to 

 affect morbid processes rather than products, to alter morbid 

 physiology rather than morbid anatomy. We do, however, 

 possess certain means of treating even structural changes 

 of organs, as we shall discover when we come to discuss 

 metabolism. 



The student is now in a position to consider the meaning of 

 two terms constantly being employed in therapeutics namely, 

 rational treatment and empirical treatment. Treatment is said 

 to be rational when it is suggested by all our chemical, physio- 

 logical, and pathological knowledge. Such treatment must be 

 successful if our observations are correct: it is founded on 

 great natural laws which are known and understood. Empirical 

 treatment is founded on experience only, and conforms to 



