DliUGS ACTING ON THE CIRCULATION 33 



which prove detrimental to the system. This Hue of treat- 

 ment is pursued in urserain, hsemoglobinsemia and lymph- 

 angitis. Venesection, saline infusions, hypodermoclysis and 

 enteroclysis alter the character of the plasma and often have 

 a life-saving value. (See p. 728-736.) 



(b) The Bed Corpuscles.— The so-called blood tonics, or 

 hcematinics influence the red corpuscles, increasing their 

 number and content of haemoglobin when there is a defi- 

 ciency of either. The effect upon the augmentation of haemo- 

 globin is more marked. 



H^MATINICS. 



Iron and its salts Corrosive sublimate 



Arsenic Potassium permanganate 



Copper salts Manganese dioxide 



The first two are immensely superior to the others in 

 blood-making properties. Iron especially favors the forma- 

 tion of haemoglobin ; arsenic increases the number of red 

 corpuscles. Certain agents possess toxicological significance 

 by destroying the composition of haemoglooin. Large doses 

 of the coal tar products, as acetanilid, antipyrin and phen- 

 acetin, nitrites and potassium chlorate, convert haemoglobin 

 into methaemoglobin, a mixture, probably, of hematin and 

 soluble albumin; while carbonic oxide, phosphorus, sul- 

 phur, arsenic, iodine, hydrogen sulphide and turpentine, in 

 large doses, reduce oxyhaemoglobin and prevent its com- 

 bination with oxygen. Acetanilid, potassium chlorate and 

 amyl-nitrite destroy the red blood cells, if absorbed in con- 

 siderable amount. 



(c) White Corpuscles. — It is possible experimentally to 

 arrest purulent exudations caused by irritation and inflam- 

 mation when quinine is introduced into the blood or applied 

 locally to blood vessels. This happens because quinine and 

 all cinchona salts, berberine sulphate and acetanilid — 

 like other poisons to amoebae — prevent the amoeboid 

 movement or migration (diapedesis) of leucocytes through 

 the vessel walls. Unfortunately it is impossible to give 

 large enough doses in practice to realize such favorable 

 results- in inflammatory disorders. An enormous increase 



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