Ill 



NOTES. 



While the above paper has been going through the press, we have seen 

 notes by Dr. Hickok to a new edition of his Cosmology. So far as we have 

 had time to examine these, they seem by no means to clear away the diffi- 

 culties which attended his first effort. The preface to these notes has at least 

 the merit of possessing a distinct and definite meaning. The fact, that now 

 and then a verb does not agree with its nominative, or a superfluous relative 

 may be detected, ought not, perhaps, to be mentioned, in view of its other 

 excellencies. 



His first note is in reply to the charge of irreverence. Since we have not 

 meddled with the theology of this work, and hence have made no such 

 charge, we shall not trouble ourselves further than to quote a single sentence 

 in which the author, speaking of the Creator, says : " We do not suppose it 

 to be any deficiency that he can not do that which is mathematically absurd." 

 We only ask that the same principle may be applied to the author's own 

 rational deductions. 



In regard to the ratio of gravity— the discussion of which we have criticised 

 with some freedom, the author has an elaborate note. He points out an ap- 

 parent absurdity in his own conclusions, and then endeavors to show how 

 perfectly his system explains it. " Inasmuch," says he, " as repulsion is in- 

 versely as the cube of the distance, and an approach to the centre must be 

 by degrees, there must be an infinite number of degrees traversed in this ap- 

 proach to the centre, and thus at the centre repulsion must be lost." Leav- 

 ing out of account the want of sequence between the premises and conclusion 

 of this sentence, we ask the author what he means by a degree. If he means 

 an infinitely short space, then there will be an infinitely large number of such 

 spaces ; but if he means any finite space, then the number must be finite. 

 Until he tells us what a degree is, we shall leave this point in suspense. 



He explains away the supposed absurdity by, "take position at once in 

 this central force, and apply the law that repulsion is as the quantity of mat- 

 ter directly, and as the cube of the distance inversely, and inasmuch as this 

 central force has all the intensity of the matter and has no distance, the sim- 

 ple and true conclusion is, that the repulsion at the centre is just (?) di-ectly 

 and only as the quantity of matter in the whole sphere." This little strata- 

 gem of jumping at once to the centre, will not help the author one iota. If 

 the repulsion follows the law laid down, then 

 Repulsion=^p 



But a very little algebra will tell the reader that the value of the right hand 

 member of this equation is infinity. So," if the author does not wish to prove 

 that which he himself claims to be "mathematically absurd," he must 

 modify again. 



In another note, the author endeavors to give an explanation of the mani- 



