Royal Society. 63 



The second work is one of more pretensions. The original 

 algebra of Dr. Wood was published afc the end of last century, and 

 was characterized by a most competent judge (the late Dr. Peacock) 

 as an admirable specimen of simple exposition, combined with 

 adequate but not excessive illustration. As time went on, how- 

 ever, parts of the work needed expansion ; and (we believe about 

 1840) Mr. Lund published an appendix to it, consisting of 

 additional propositions and examples. In 1845 he incorporated 

 this appendix with the original work, some parts of which he 

 omitted, e. g. that on the theory of Equations. The present 

 edition differs from that of 1845 in several minor respects, but 

 embraces nearly the same topics. Perhaps the chief difference 

 between the editions is that the present contains a much larger 

 number of examples than the former. The addition is made in 

 three ways, viz. by appending to each section of the work 

 numerous easy examples, by increasing the number of harder 

 examples at the end of the book, and by adding three series of 

 Miscellaneous Examples, and twenty-four papers of Questions in 

 Algebra which have been recently set in University Examinations 

 at Cambridge. 



It marks a real advance in Education that the present work, 

 originally designed for Students in the University, should have to 

 be adapted, and on the whole with large additions, for use in 

 Schools, because the subject is now almost universally taught in 

 them. At the same time we cannot help feeling a doubt whether 

 it is not a mistake to insert in elementary mathematical books the 

 enormous number of examples which they now ordinarily contain. 

 Their insertion is, of course, a consequence of the effort which 

 teachers have to make in order to qualify their pupils for com- 

 peting with the ingenuity of examiners. Surely, however, if the 

 question were merely one of education, a lad of seventeen or 

 eighteen might with advantage have his attention directed to other 

 subjects long before practice had made him pretty certain of solving 

 such an equation as 



by his own lights and without a knowledge of Cardan's Eule. 

 X. Proceedings of Learned Societies, 



EOYAL SOCIETY. 



[Continued from vol. i. p. 326.] 



Jan. 13, 1876.— Dr. J. Dalton Hooker, C.B., President, in the Chair. 



^HE following paper was read : — 



u On the Optical Deportment of the Atmosphere in reference 

 to the Phenomena of Putrefaction and Infection." By John Tyn- 

 dall, E.E.S. 



The author refers in an Introduction to an inquiry on the de- 

 composition of vapours and the formation of active clouds by light, 



