54 Sir B. Brodie on the relative [Jan. 24, 



a 3 x 6 



unit of 



benzene. 



«V 8 



unit of dipheuylbenzene. 







phenylacetylene. 



a 7 x 20 





dinaphthyl. 



a 4 * 3 





propane. 







idrialin. 







butylene. 



aV 





heptane. 



a 4 * 5 





valerylene. 



a 8 x s 





octylene. 



aV 





toluene. 



« 8 X 9 







a v 





cinnamene. 



a 8 K 10 





terpene. 



a 4 x 10 





naphthalene. 



« 8 x" 





aniylbenzene. 



sAcB 





ethine naphthalene. 



a 8 * 14 





anthrcaene hexhydride. 



a 5 * 4 





tetrane. 



a 8 x 15 





benzylxylene. 



a 5 x 3 





aniylene. 



« 8 x 19 





triphenylmethane. 



a 5 x 6 





diallyl. 



a 9 x 8 





octane. 



aV 







a 9 x 9 





nonylene. 



a 5 x 8 





xylene. 



«V° 





rutylenai 



a*x 9 





allylbenzene. 



aV* 





amyltoluene. 



a 5 x 10 





dihydronaphthalene. 



a 9 K 16 





benzylcuniene. 



a 5 x" 





methylnaphthaleue. 



aV 8 





tetramethylanthracene. 







diphenyl. 



a 9 x* J 





tolyl diphenylmethane. 



aV 3 





fluorene. 



«V 24 





triphenylbenzene . 



a V 4 





anthracene. 



a 10 x 9 





nonane. 



a 5 x* 





pyrene. 



a 10 x 10 





diamylene. 



a 6 x 5 





pentarie. 



a ln x 13 





amylxylene. 







hexylene. 



a l 0)C 26 





tetraphenylethylene. 



a 6 /c' 





cenanthylidene. 





33 



decane. 



a 6 x 9 





cuniene. 



a"x26 





tetraphenylethane. 



a 6 /c 10 





phenylbutene. 







endecane. 



a fi x 12 





ethylnaphthalen e . 



a l -'x 19 





dimesityl methane. 



« 6 X 13 





diphenylmethane. 







dodecane. 



aV 4 





stilbene. 



a^V 3 





tridecane. 







methylanthracene, 



« 14 x 15 





benylene. 













tetradecane. 



a r >x 18 





chrysene. 



a 15 K 15 





triamylene. 



a'x* 





hexane. 



a 15 x 16 



33 



cctenylene. 



a'y.' 





heptylene. 



a 16 x 15 





pentadecane. 



a'^ 





caprylidene. 





33 



cetene. 







cyniene. 



a 17 K i6 





hexdecane. 



aV 4 



33 



benzyltoluene. 



a 20 K 20 



33 



tetramylene. 





53 



diniethylanthracene. 



a^x 2 ' 



33 



cerotene. 



a"x 17 



33 



naphthylphenylmethane. 







melene. 



With, tlie view of effecting a comparison between the hydrocarbons 

 actually produced and their relative " facility of production," as in- 

 dicated by theory, I have constructed the following map.. The nature 

 of this map will be readily understood from inspection. So far as the 

 numbers are concerned, it is the arithmetical triangle of Pascal. Each 

 square contains a number, and the symbol of a hydrocarbon. " A line 

 drawn so as to cut off an equal number of units from the top hori- 

 zontal row and the extreme left-hand vertical column, is called a base. 

 The bases are numbered, beginning from the top left-hand corner. 

 Thus, the tenth base is a line drawn through the numbers 1, 9, 36, 



