MATERIA MEDICA AND THERAPEUTICS. 17 



isms or parasites which live upon the body, as sulphur, iodine, mer- 

 curial ointment, etc. 



Germicides. — A general term meaning to destroy germs of 

 any kind whether bacilli, spirilli or micrococci. 



Antiperiodics. — Check the progress of certain periodically re- 

 curring diseases, lessening the severity of their attacks and pre- 

 venting their return ; probably by a toxic action upon the microbes, 

 whose development in the blood by successive crops is supposed 

 to cause the disease. The great antiperiodic is quinine, next in 

 efficiency is arsenic, others are salicin and the other alkaloids of 

 cinchona, also iodine and eucalyptus. 



REMEDIES ACTING ON THE SURFACE OF THE BODY. 



These are termed rubefacients, vesicants, suppurants, caustics, 

 setons, actual cautery, astringents, demulcents, emollients, and 

 diluents. 



Irritants. — In general when, applied to the skin stimulate or 

 inflame it by attracting an increased flow of blood to the part, 

 and by reflex action produce certain remote effects, then they are 

 called counter-irritants; they relieve or remove congestion, in- 

 flammation and pain and by stimulating functional activity pro- 

 mote repair. 



IRRITANTS ARE SUBDIVIDED INTO THE FOLLOWING GROUPS, viz. : 



Rubefacients. — Produce slight redness of the skin, due to 

 congestion of the capillaries, such are mild ammoniacal solutions, 

 mustard, iodine, mild cantharides ointment, etc. 



Bpispastics — Vesicants or Blisters. — Are more active and 

 deep-seated, they inflame the skin and raise vesicles or blisters 

 (blisters contain a serous fluid composed of about 78 parts water, 

 18 of albumen, 4 of salts and a little fibrin). 



Cantharides and strong ammonia are mostly used. 



Suppurants or Pustulants:- — Actively inflame the deep-seated 

 cutaneous tissues, especially the orifices of sweat glands and cause 

 pustules and a purulent discharge. 



Red iodide of mercury is most commonly used; others, as 

 croton-oil, euphoribum ; the vesicants also will act as suppurants 

 when repeated on same spot. 



Cauterants or Caustics. — Combine with the water and albu- 

 men of the tissues and cause separation of a slough. 



