120 ON THE THEORY OF TYPES IN CHEMISTRY. 
above all, with free institutions which are the envy of less favoured 
lands: if, amid all its eager pursuit of material wealth, it could point 
to no phalanx of labourers aiming at the increase of the wealth of 
mind; to none who covet being sharers in that glorious advance- 
ment of knowledge by which God, who has revealed himself to 
us in his word, is making ever new revelations of himself in his 
works; and having made known to us Him who is the wisdom and 
the power of God, through whom we have the assurance of life and 
immortality in the gospel of his grace; is anew, in the great volume 
of nature, adding fresh evidence of man’s immortality, by revelations 
of the inexhaustible wonders of that creation, which, I doubt not, is. 
to employ the purified and enlarged faculties of man in its study 
through all the ages of that future life to which it is his atribute to 
aspire. May we, while seeking here the pure and elevating enjoyments 
which spring from the discovery of nature’s truths, find knowledge 
of the humblest works of God an incitement to the adoration and love 
of Him, whom to know is life eternal. 
ON THE THEORY OF TYPES IN CHEMISTRY. 
BY T. STERRY HUNT, M.A, F.BR.S. 
In the <Annalen der Chemie und Pharmacie for March, 1860, 
(exiii., 293) Mr. Kolbe has given a paper on the natural relations 
between mineral and organic compounds, considered as a scientific 
basis for a new classification of the latter. He objects to the four 
types admitted by Gerhardt, namely, hydrogen, hydrochloric acid, 
water, and ammonia, that they sustain to organic compounds only ar- 
tificial and external relations, while he conceives that between these 
and certain other bodies there are natural relations having reference 
+o the origin of the organic species. Starting from the fact that all 
the bodies of the carbon series found in the vegetable kingdom are 
derived from carbonic acid with the concurrence of water, he pro- 
ceeds to show how all the compounds of carbon, hydrogen and 
oxygen may be derived from the type of an oxide of carbon, which 
8 either C,0,, C,Q,, or the hypothetical C,O. 
When in the former we replace one atom of oxygen by one of 
