xiv.] FORBES " SCIENTIFIC WORK. 483 



express a mode of calculating a method rather than a 

 theory. One does not say the differential theory, but 

 the differential calculus, and e converse I should rather 

 say theory of probabilities than calculus. I like your 

 phrase " the laws of random." . . . 



* Yours very truly, 



1 K. L. ELLIS.' 



To what extent these and other very numerous sugges- 

 tions and criticisms were taken advantage of by Forbes 

 in finally preparing his paper for publication we can only 

 roughly um-ss, inasmuch as we are not in possession of a 

 copy of the original proof submitted to the critics. Forbes 

 him s in a postscript that several modifications 



and additions had been made, and that he had profited 

 liy tin- kind criticisms of several friends to whom he 

 submitted the argument. The paper as it stands, in the 

 Philosophical M<'</<>-.ine for December 1850, is well 

 worthy of careful perusal, but in no wise from a mathe- 

 matical point of view. Experiments, indeed, performed 

 1 ropping rice-grains through a sieve upon a chess- 

 d, and counting the number on each of the squares, 

 are given in illustration; but, so far as we can see, the 

 T is much too diffuse, and one or two pregnant 

 aces from the letters we have quoted might here 

 and then- have been substituted with advantage for whole 

 sections together. The conclusions, however, must be 

 given in Forbes' own words: 



' (1.) The fundamental principle of Mitchell is erro- 

 neous ; the probability expressed by it is an altogether 

 different probability from what he asserts. His calcula- 

 apparently inaccurate, in some instances at 



'(2.) All the. .(/ deductions of his successors are 



Were Mitchell's principle just, a perfectly uni- 

 and symmetrical disposition of the stars over the 



1 'It v. correct to say Unit nil Mitel: 



r ilrul.'ition.s 'in* wrongly his <>\vn premises.' 



I I -J 



