Mineral Substances of Organic Origin. VI. Guyaquillite. 331 



Burned with oxide of copper from which the moisture had 

 been well pumped out, 



7*538 grs. gave 20*9 grs. of carbonic acid and 5*54-5 of water. 



, 8-415 grs. — 23*54<grs. 6-208 



These are equivalent to 



I. II. 



Carbon = 16-665 77*350 



Hydrogen... = 8*174 8-197 



Oxygen = 15*161 14-453 



100* 100* 



The formula Cgo H,3 Og gives the proportions 



20 C = 1528*750 = 76*783 



13 H= 162*2348 = 8*148 



3 O = 300-000 = 15*069 



1990-9848 100* 



It is difficult to determine what is the rational formula of 

 this compound. It may either be an oxide 



^20 Hi3 + Og, 



or a hydrate C20 Hjo + 3 H O, 



Q in which 



three equivalents of hydrogen are replaced by three of oxy- 

 gen. 



The ratio of the carbon to the hydrogen, 20 : 13, renders it 

 unlikely that it is a simple oxide ; and that it is not a hydrate 

 is rendered very probable by the fact that the ratio of these 

 two elements remains the same in the guyaquillate of silver. 



Thus a portion of a silver salt of a dark colour gave on 

 burning with oxide of copper, 



Carbon = 17*675 = 20 atoms. 



Hydrogen ... = 4*754 = 13*22 atoms. 



{ — 3 H 

 Q or simply 



C20 Hjg Og, gives the most probable representation of the true 

 constitution of this substance. Of course the relation to oil 

 of turpentine indicated by the formula, though interesting and 

 agreeing with the doctrine of substitutions, must be viewed 

 with distrust, till the geological position and probable origin 

 of the mineral be more fully investigated. It is easy to sup- 

 pose it, like amber, of vegetable origin, and to occur in consi- 



