Constitution of the Resins. 



311 



Group I. 

 II. 



= C40 H32_,0^ 



In these groups x can never exceed 8, and there may be 

 other groups, none of the members of which are yet known, 

 of which Hg-j- Hjg_^, H4o_^, may form the middle term. 



Each of these groups is divisible into many subgroups, in 

 each of which 3/ is represented by a different number. Thus 



Group I. = C^o^32-^^.y 



Subgroups. To which belong 



A r> H n /Anime resin =C4oH32 0i 

 A = U40 H32_, u, ^YossW copal = C,o H32 O, 



Elemi resin = C4Q Hgj O^ 

 Mastic B = C.n H., Oc, 



B = C40 H 



O. 



{1 



Laurent. 

 Johnston. 



Rose. 

 Johnston. 



Vy ^ACl HjlO—J 'J 



■40 ^■'32— J 



D = C40 Hoo_j O 



E = Cac Hqo_, = 



1 H31 03 



o. 



— ^40 



Hg 



. H 



II = C^ H 



'40 "32-* 





{Anime B ^ _ p 

 Copal B / - '"'' 



r Colophony = C^ H^ 

 ' \Mastic A = C40 H31 O4 



f Modified \ _ r vf n 



I colophony J " '"4o "27*^5 

 , < Modified 1 



I mastic A > = C^q H3, O5 



[^ JuniperAJ 



r Resin of \ _ p tt pj 



^ GuyaquilJ " ^^o "26 '-'s 



(^Asphaltene ? = C40 Hgg Og 



no examples yet known. 



C Pasto var- ) pun 



^Af\ -ttoo Vyo 



I 



Group II. 



Subgroups. 



A = C.„ H 



= C 



'40 ^••24— *• 



o 



J nish J 



i Berengela I _ n H O 

 L resin J " ^^o "^i '^ 



10 H24_^ O j/ 



To which belong 

 r Resin of dragon's blood = 



do. 



Liebig. 

 Johnston. 



do. 

 do. 



do. 



Boussin- 

 gault. 



do. 

 Johnston. 



B = C40 H24_j O 



*-" ^^ ^40 "24— * O 



Resin of gamboge 



Resin of guiacum 

 Acaroid resin 



40 "21 Og 



40 "23^8 



— C40 HgsU], 



=^ Cln Hon vJi 



-^40 ^-"20 



This second group I have only just established, and other 

 subgroups will present themselves in the progress of the in- 

 vestigation. You will observe that the subgroups compre- 

 hend divisions in which the equivalents of hydrogen vary so 

 that the number of substances which may belong to this na- 

 tural family is almost endless. The details of the analyses 



