138 ALTERATIVES INFLUENCE METABOLISM 



When nervous functions are imperfectly performed, nervine 

 tonics are appropriate. Cold, in the form of baths, douches, 

 and sponging, proves a valuable tonic, applicable for 

 general as well as local purposes, relieving irritability, 

 bracing up soft, flabby textures, and equalising circulation. 



H^MATINICS, or blood tonics, constitute an important group 

 of tonics, which increase the number of red corpuscles and 

 the quantity of haemoglobin in the blood. The red blood 

 corpuscles are formed chiefly in the red marrow of bones, 

 especially in the vertebrae and ribs. Red corpuscles are in 

 great part destroyed by the liver and spleen, and it hence 

 appears possible that disorder of these organs is a cause of 

 the anaemia, which is very common amongst badly reared 

 young animals. Anaemia is of two kinds : (1) where there 

 is a normal number of red cells all more or less deficient in 

 haemoglobin (chlorosis) ; (2) where there is a definite short- 

 age of red cells. The former variety is frequently due to the 

 insufficient absorption of iron to supply the haemoglobin, 

 whilst the latter may result from haemorrhage or from 

 haemolysis due to disease toxins, or poisons such as lead. 

 Then again, anaemia may often be due to malnutrition, un- 

 suitable or insufficient food, digestive diseases, or the effects 

 of parasites. In order to restore iron and fatty matters 

 which are deficient in anaemic blood, daily doses of soluble 

 iron salts are prescribed, while easily assimilated fatty 

 matters, such as boiled linseed, or linseed cake, are given to 

 horses and cattle, and cod-liver oil to dogs. An improve- 

 ment of general health is further effected by judicious feed- 

 ing and comfortable quarters. The anaemia resulting from 

 debilitating disease requires similar treatment. To ensure 

 their good effects, tonics are generally given in moderate 

 doses, two or three times daily, for several days, or for weeks, 

 and throughout their administration the bowels should be 

 kept in a normal state. 



ALTERATIVES are defined as drugs which influence the 

 amount and kind of tissue change going on in different organs 

 and cells. Their results are usually readily recognised, but 

 the way in which they are produced is difficult to explain. 

 With the better understanding of pathological processes 

 and the pharmacological actions of drugs, this term is falling 



