980 MODUS OPERANDI OF 



brane. Thus it is by giving a preponderance 

 to the lymphatic absorbents over the nutritive 

 process, that such medicines produce their effects. 

 Nor can there be a doubt that nearly all the more 

 active articles in our Materia Medica impair the 

 vital properties of the blood, and, relatively, in- 

 crease absorption. 



For example, it was found by Orfila, that by 

 injecting a dram of the liquor ammoniae into the 

 jugular vein of a strong dog, convulsions imme- 

 diately followed, and death in ten minutes. The 

 same effects are produced in a much shorter time 

 by injecting a few grains of caustic potash into 

 the veins of a dog. Liebig maintains that alco- 

 hol, and most of the neutral salts, operate by ab- 

 stracting water from the moist tissues. But we 

 have seen from the experiments of Magendie, 

 (referred to in a note to pages 653-4 of this work,) 

 that, when mixed with fresh blood as soon as 

 taken from the body, they all destroy or greatly 

 retard its coagulation. He also found that very 

 small proportions of carbonate of soda, carbonate 

 of potash, carbonate of ammonia, nitrates of pot- 

 ash, lime, and other alkalies, produced the same 

 effects : that soon after injecting less than an 

 ounce of carbonate of soda into the veins of a 

 dog, he was attacked with dyspnoea, small and 

 frequent pulse, prostration of strength, conges- 

 tion of the lungs and abdominal viscera, effusions 

 of blood, and all the symptoms of malignant 



