PHILOSOPHICAL WHITINGS OF THE LATE DR. DALTON. 5 



in some late elements of chemistry written in French/' With 

 regard to Query 3, he urges that " the reason why the sun, 

 shining upon the fire, renders it so languid, seems to be owing 

 to its rarefying the circumambient air; for it has been proved, 

 from a variety of experiments by Boyle and others, that com- 

 bustible bodies burn with more or less vehemence, as the air 

 they are in is condensed or rarefied." In answer to Query 4, 

 he cites the Scriptures^ Aulas Gelllus, and Chamber8*s 

 Cyclopccdia^ in proof of the antiquity of the use of the ring 

 in marriage, and also when conferring particular honour on 

 individuals. "The Greeks," he observes, "always wore the 

 wedding ring on the fourth finger of the left hand," and the 

 reason for it is, " that having found from anatomy that this 

 finger had a little nerve which went straight to the heart, 

 they esteemed it the most honourable by reason of this com- 

 munication with that noble part." His correspondence to the 

 mathematical department of this Diary is somewhat extensive. 

 He answers thirteen questions out of the Jifteeii proposed, 

 and is so far successful as to have three of these inserted at 

 length. The first solution corrects several errors in Hawney's 

 Mensuration, relative to regular polygons; the second affords 

 sufficient evidence that mechanics and fluxions had engaged 

 his attention ; whilst the third appears worthy of transcription, 

 in proof that the higher branches of natural philosophy had 

 at this time been cultivated by him with success. During 

 this year he also proposed the following questions for solution, 

 the latter of which forms Question 593 of the GentlemarCs 

 Dianj^ at this time under the able management of the Rev. 

 Charles Wildbore, who, under the signature " Eumenes," 

 supplies an elegant geometrical solution to Mr. Dalton's 

 question :— 



Ladies Diary, 1788. Question 884. By Mr. John 

 Dalton. "In the semicircle ACB, whose diameter is AB, 

 and OC perpendicular to it from the centre, from B there is 



