380 [Jan. 8, 



Zoneless polar edge : 



Zonal non-polar edges : 



(33)*o4lO=8, Z={4, 2, 0, O 3 } ; 



(33)* 410=1, Z = {2, 2, 0, 0}; 



(33)*o410 = 5, Z = {4, 4, O 2 , 02}; 



(33)* 410=2, z={4, .., O 4 }; 

 (33)* 410=2, Z={6, 2, 0, O 5 }. 



Objanal zonal edge : 



(33)a410=l, Z={2.2, 2.2, O 2 - 1 , 0"}, 

 which is also above entered as zonal. 

 Epizonal edges : 



(33)^410=3, Z={4, 2, 0, O 3 }; 



(33) e| >410=l, Z={2, 2, 0, 0}; 



(33)^,410=3, Z={4, 4 O 2 , O 2 }; 



(33) ep 410=l, Z={2, 4, O 2 }. 



Asymmetric edge : 



(33),410=83. 



I may be permitted to remark here that these results were in my 

 possession early in 1858, when the prize question of the French 

 Academy was published for the competition of 1861 : " Perfectionner 

 en quelque point important la theorie geometrique des polyedres" 

 My work on this theory was first completely composed in the French 

 language, in its present form, with the intention of presenting it to 

 the Academy in 1861. Any person, who cares to know the reasons 

 why I altered its destination, may read them at page 352 of the 

 ' Memoirs of the Literary and Philosophical Society of Manchester/ 

 3rd series, vol. i. 1862, beginning at the second line ab infra. 



II. " Contributions towards the History of the Monamines. 

 No. VI. Note on the Action of Iodide of Methyl on Am- 

 monia." By A.W. HOFMANN, LL.D., F.R.S. Received 

 December 2, 1862. 



When studying, many years ago, the action of iodide of methyl 

 upon ammonia, I pointed out the existence of dimethylamine among 

 the products of the reaction. The amount of iodide of dimethylam- 



