494 TRANSACTIONS OF THE 



heat were compelled to adopt the habits of the Esquimaux and 

 came to eat train oil and candles with as good relish as those chil- 

 dren of the North. But as the furnaces for the consumption of 

 anthracite coal are of a different construction from those for the 

 consumption of wood so the digestive organs of an Esquimaux 

 differ from ours. Nature, all kind, modeled the Doctor's furnaces 

 as far as might be after the Arctic fashion for digesting and con- 

 suming the most substantial fatty matter, and to such an extent 

 that they answered the purpose pretty well. On his return to 

 this country the reverse process was performed in a measure, but 

 his constitution failed. Under these circumstances he unfortu- 

 nately asked her to further adapt his heat-producing organism to 

 a tropical climate, and in making the attempt she destroyed him. 

 Thus, as an eminent surgeon of our own country once re- 

 marked, " do men often die getting well." 



The North American Indian is a further illustration of this 

 law. Naturally the most carnivorous of men, he is most given 

 to motion and cannot be civilized for organic reasons. Like the 

 partridge he cainnot be made to live on civilized food. Spirits 

 that I am sorry to say are at the extreme end of civilized diet, 

 containing no nitrogen, are so fatal to him as to have received the 

 appellation of fire water. There is a limit then in the individual 

 beyond which if the necessity of modification be urged the result 

 is death. 



As the limits of variation are determined in animals by the 

 variety of their food, so they are determined in plants in the same 

 latitudes by the different soils they may inhabit, and consequently 

 the different inorganic constituents that may be expressed in their 

 ashes. For these reasons the cultivated plants vary more in their 

 analysis than any others, inhabit a greater range and are never as 

 reliable for medicinal use as the wild ones. 



LAW OF VARIATION. 



The typical animal and plant have been developed into differ- 

 ent varieties by the process of adaptation. The forms of the trees 

 in our primitive forests are very different from the forms which 

 the same trees assume when growing in the open plain. When 

 the topmost sprout of the spruce, which runs up into a single 



