186 EUROPEAN AGRICULTURE. 



for this purpose act : these being set in motion by the heart, this 

 again by the nervous system, and the latter by respiration, there 

 is discernible a beautiful chain of connection between the oxy 

 gen of the atmosphere and the absorbed food. If the system 

 described were always in equable movement, if no influences 

 were occasionally present to interfere with its proper equilibrium, 

 animals would be in the condition of plants, which possess ab 

 sorbing apparatus, but are destitute of one powerful interfering 

 agent in the animal economy ; this is the brain and nervous 

 system, upon the condition of which depend passions and emo 

 tions of the mind. It is principally by the study of this impor 

 tant apparatus that we derive our knowledge of what is pecu 

 liarly termed the constitution of animals. Without this system, 

 animals would be merely chemical machines, and we might then 

 predicate, in every case, the effects of particular influences, as 

 one animal would then differ from, another merely in the extent 

 of its mechanism. This remark is to be kept in view in consid 

 ering the subsequent experiments. The cows were very differ 

 ent in reference to their nervous condition. The white cow was 

 quiet and steady, generally eating equal portions and producing 

 equable quantities of milk. The brown cow, on the contrary, 

 was fitful in her appetite, and, of consequence, was variable in 

 the amount of her products. In proportion to her weight, she 

 consumed a larger amount of food than her fellow, but always 

 afforded less milk, and a greater amount of butter. The va 

 riable action of her organs is well exhibited in the first series of 

 tables. When at pasture, she had given two pints less than the 

 white cow, and immediately before the experiments, she gave 

 the same quantity as her fellow. On her arrival in Glasgow, her 

 milk greatly increased; but it soon began to diminish, although 

 the same amount of food was continued. That the change was 

 not produced by any alteration in the food is obvious from the 

 steadier result afforded by the white cow, which was also sup 

 plied with an equal weight of fodder. The amount of milk 

 given by the brown cow was as much as 26 Ibs. per day, when 

 she was fed with grass, and upon the same kind of food the 

 quantity declined to 22 Ibs. ; while the milk produced by the 

 white cow was, at the commencement of the experiment with 

 grass, 23 Ibs., and at the termination of the trial 21 Ibs. ; so that 

 there was a falling off, in the case of the brown cow, to the 



