126 



inches, of the female from 63 '2 to 61*6 inches; while the mean 

 weight of the former varied from 112*12 to 91*5 Ibs., and of the 

 latter from 95*2 to 76*9 Ibs., showing a preponderance of the insane 

 male of 6 Ibs., and of the insane female of 8 Ibs., as compared with 

 the sane adults dying at the same period of life. 



The average weight of the right cerebral hemisphere varied in the 

 males from 20-89 oz. to 18'97 oz., and in the females from 19'21 oz. 

 to 1 7'20 oz. ; the left varied in the males from 2T05 oz. to 18'62 oz., 

 and from 19'51 oz. to 17'39 oz. in the females. It is a singular fact, 

 confirmed by the examination of nearly 200 cases at St. Maryle- 

 bone, in which the hemispheres were weighed separately, that 

 almost invariably the average weight of the left exceeded that of the 

 right by at least the eighth of an ounce. In the Med. Chir. Trans, 

 vol. xxxix., several cases of inequalities of the cerebral hemispheres 

 which came under my notice are given. The average weight of the 

 cerebellum varied in the males from 5'42 oz. to 5'06 oz., and from 

 5 to 4 '74 oz. in the females ; that of the pons Varolii and medulla 

 in the male from 1*15 oz. to 1*02 oz., and from 1*05 oz. to *95 oz. in 

 the females; and that of the encephalon in males from 48' 17 oz. 

 to 43'87 oz., and in females from 44*55 oz. to 40*55 oz. ; in the sane, 

 at the same period of life, the average varied in the male from 48 '2 

 oz.to 45*34 oz., and in the female from 43*7 oz. to 39'77 oz. 



The general average weight of the lungs is shown in the Table, 

 and the exceptions in the margin. The average weight of the heart 

 did not reach its maximum until an advanced period of life. 



In the Abdominal organs nothing was observed differing essentially 

 from those in Table No. 1. 



fits \ 



II. " On the Electric Conducting Power of Copper and its 

 Alloys." By A. MATTHIESSEN, Ph.D. Received Feb. 14, 

 1861. Communicated by Professor W. THOMSON, F.R.S. 



The difference in the numerical results obtained by Prof. W. 

 Thomson (Proceedings of Roy. Soc. 1859, x. p. 300), and those by 

 Dr. Holzmann and myself (Phil. Trans. 1860), on the conducting 

 power of copper and its alloys, made it somewhat necessary to re- 

 investigate the subject, in order to ascertain the cause of these dif- 

 ferences. For this purpose Professor Thomson kindly placed at my 



