THERAPEUTICAL ACTION ON THE BLOOD. 451 



frequency of the pulse and breathing compensate for want of 

 haemoglobin. Unfortunately there is here as elsewhere a limit 

 to recovery, as when large quantities of a poison, such aa 

 carbonic acid, have entered the blood, or when the haemoglobin 

 has been reduced. 



V. THERAPEUTICS. 



The facts which we have reviewed under the four preceding 

 heads are highly encouraging to the practical therapeutist. 



In plethora he will reduce the amount of food, increase the 

 excretions, and prescribe increased bodily exertion; five-and- 

 forty years ago he would have bled the patient freely, and 

 repeated the operation at regular intervals. 



Anaemia must be treated by the opposite class of measures, 

 which will be discussed immediately under the head of the 

 red corpuscles. Speaking generally, we must sustain and 

 restore the appetite and digestion, spare the body every possible 

 exertion, maintain healthy excretion, and, if the condition 

 be urgent, even transfuse blood into the veins. Deficiency of 

 albumen is met by the same measures. Excess of carbonic acid 

 demands artificial respiration, as we shall find under respiratory 

 diseases. 



When the indication is to increase the alkalinity of the 

 plasma in rheumatism, gout, and allied morbid states, we 

 administer salts of Potash, Soda, Ammonia, Lithia, or the 

 Alkaline Earths, the Alkaline Citrates and Tartrates being the 

 most suitable because large quantities can be admitted into the 

 blood without deranging digestion. Acids, which have so little 

 influence in the opposite direction, are fortunately seldom called 

 for. The treatment of poisons in the blood, whether formed 

 in the body or introduced from without, will rationally consist 

 first in removing their cause, e.g. indigestion or renal disorder, 

 or in decomposing or neutralising them chemically. This 

 introduces us to the second use of alkalies in the blood. The 

 acid of rheumatism, whatever it may be, and the uric acid of 

 gout, are converted into soluble salts by the Alkalies and Alka- 

 line Earths, and these salts are fortunately diuretic. In this 

 way excess of acid is not only neutralised, but conveyed out of 

 the system, and the reaction of the urine may be used as a 

 test of the success of our action on the blood. This end is 

 secured in acute cases by the free exhibition of the milder 

 salts of Potash, Soda, Ammonia, and Lithia; in chronic cases by 

 treatment at an alkaline bath, such as Ems, Homburg, Vichy, 

 Carlsbad, Buxton, or Bath. Metallic poisons, such as lead, 

 are removed from the blood and tissues in precisely the same 

 way; lead, for example, by Iodide of Potassium or Sulphur baths. 



