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220 QUARTERLY JOURNAL. 



is perhaps as important as any other. It is the wide diffusion 

 of these essential elements. If phosphate of lime was confined 

 to veins and beds, and those only of the limited extent 

 which we usually find them, this material would rarely exist 

 in the soil. It might abound in some places, but it would be j 

 very deficient in others. What is especially required to meet the Hi 

 wants of every living being, is that those essential materials should 

 exist every where, should be universally distributed. Such is 

 eminently the case with those four gaseous bodies which enter, it 

 may be said, into every living thing, viz : oxygen, hydrogen* 

 nitrogen and carbon. Oxygen, is the controlling element, 

 its peculiar properties rendering the three others subservient to 

 organic wants ; hydrogen entering into bodies in water, nitrogen 

 in ammonia, and carbon in carbonic acid. The diffusion of car- 

 bonic acid is an important fact — important as a provision. The 

 atmosphere always contains it. If it is disengaged from volcanoes^ 

 it is speedily and equally distributed through the body of the atmos- 

 phere by the law of the diffusion of gases, and by winds. In 

 consequence of its ready solubility in vapor, it is brought to the 

 earth where it may be appropriated to the uses of plants. That there 

 should be no want of this substance, it is largely stored up in lime- 

 stones, which are not of themselves insoluble, like silica or sand. 

 From the air, and from both ancient and modern rocks, carbon is 

 furnished in undiminished quantities, and such is the arrangement 

 that the sources will remain and go on furnishing all the carbon 

 required ad infinitum, though every part of the earth may be cul- 

 tivated and be made to produce double the amount it now pro- 

 duces. 



There is still another point worthy of attention, as well as ad- 

 miration, it is the condition which fits it for organization. For 

 example, by way of illustrating the thought, had carbonate ot 

 lime been employed as the material for constituting the bones ol 

 animals what would have been the result 1 From the tendency of 

 this substance to crystallize, it is believed that this form of lime 

 would not only have formed bones of little strength, but it would 

 requently by this property, injure the softer structures as it can- 

 not accommodate itself to the delicate animal fibres. 



We have spoken of prospective arrangements ; we now remark 

 that of all the arrangements termed prospective, all yield in im- 



