524 THE ROYAL SOCIETY OF CANADA 



evidence necessarily connecting this edition with Brown's purchases. 

 If the narrative is intended for readers with a double interest, on the 

 one hand, in Brown's purchases of the Annals, and, on the other, in 

 the merits and prices of various editions of the work, the whole of 

 Part 2 would be included at once in the narration. In Part 3 the 

 reference to the recent edition being more elaborate and larger than the 

 second edition would be dealt with similarly; and in this part also 

 the statement that the second edition bought by Brown had no illus- 

 trations, would be excluded there from a narrative with a single 

 interest in Brown's purchases, as being purely negative. The point, 

 however, would be included at once in a narrative with the double 

 interest, because, in readers interested in the merits and prices of the 

 various editions, the information that the recent edition is illustrated 

 arouses curiosity whether the earlier one had illustrations too and 

 for such readers this negative information has a positive interest. 

 Thus the respective narratives of necessary conclusions at Part 4 

 will read as follows, the one with the single interest being in the left 

 column, and the one with the double interest in the right: 



"Brown, who is interested "Brown, who is interested in old 



in old books, especially the books, especially the novels of John 



novels of John Gait, recently Gait, recently expended 22s. 6d. in 



expended 22s. 6d. in buying buying that author's Annals of the 



that author's Annals of the Parish. He has a copy of the first 



Parish. He has a copy of the edition, issued in 1821, and of the 



first edition, issued in 1821, and second, issued in 1822. He paid 4s. 



also of the second, issued in for the latter edition, which was 



1822, having paid 4s. for the published originally at 8s. retail and 



latter edition which was pub- has no illustrations and is otherwise 



lished originally at 8s. retail." less elaborate and smaller than a 



recent illustrated edition selling at 



5s. retail." 



In Part 5 it is brought into evidence that Brown bought a copy 

 of the recent illustrated edition, and therefore the single and double 

 interests coincide in Parts 5 and 6. The final narrative of necessary 

 conclusions, for either interest, may be re-arranged as follows: 



"Brown, being interested in old books, especially the novels of 

 John Gait, recently expended 22s. 6d. for three editions of that author's 

 Annals of the Parish: 6s. for the first edition, issued in 1821; 4s. 

 for the second, which was published in 1822 at the retail price of 8s. 

 and has no illustrations and is otherwise less elaborate and smaller 

 than a recent illustrated edition selling in buckram at 5s. retail; 



