530 
In the beginning of this memoir he recognizes the assistance 
which has been afforded to Zoology by the sister science of Geology, 
in adding the remains of a former world to enrich the stores and 
supply the deficiencies of the present time, increasing the materials 
of zoology to an extent, which the most sanguine views of its culti- 
vators could scarcely have anticipated. To the fifteenth volume of 
the Linnean Transactions he contributed, in conjunction with Dr. 
Horsfield, a Description of the Australian Birds in the Collection 
of the Linnean Society, arranging them according to their natural 
affinities, with general Observations on the Zoology of New Hol- 
land. His sketches in Ornithology, and observations on the 
leading affinities of some of the more extensive groups of birds, 
form a series of instructive and valuable memoirs in the Zoological 
Journal; in the second volume of which, p. 391, in a memoir on 
the arrangement of the genera of birds, he published a tabular . 
sketch, representing a summary of his views of the affinities and 
analogies of the generic groups he proposes to establish in this 
family. These masterly essays give evidence of an acute and deli- 
cate perception of the distinctions of species, combined with power- 
ful comprehensive views of the relations of genera to each other, 
and to the families which’combine to make up the entirety of the 
.animal kingdom. They are also interspersed with a variety of 
illustrations from ancient authors, which show him to have had 
considerable taste and extensive knowledge of classic literature. In 
1811 he published his “Inquiry into the Nature and Extent of 
Poetic License,” an ingenious and elaborate work, of which a 
second ‘edition appeared in 1813. His later works in Natural 
History appear in the Transactions of the Linnean and saga 
Societies, and in the Zoological Journal. 
In Mr, Witrsam Macture we have lost an early and useful ve 
bourer in the field of geology, to whom we owe the first connected 
and systematic accounts of the structure of North America reduced 
to a comparison with that of Europe. 
He was born at Ayr in 1763, and educated in that town. In 
1782 he visited New York, and returning to London became a part- 
ner in an American mercantile house. He visited France several 
times between 1782 and 1796, when he went to Virginia and closed 
his business there as'a merchant. In 1803 he returned to Britain, 
and was appointed a Commissioner for settling the claims of the 
United States against France. From Paris, as a centre, he after- 
wards made scientific tours over a large portion of Kurope. 
In 1807, returning from Europe, he commenced single-handed 
the Herculean task of exploring the geology of the United States; 
and after several years of labour, during which he crossed the Al- 
leghany Mountains not less than fifty times, he produced a geological 
map of the whole country, which, though it gives only the Wer- 
nerian classes of rocks, forms a most valuable outline, and is a monu- 
ment’ of great industry, perseverance and intelligence*. 
His first observations on the geology of the United States, ac- 
* See Hitchcock’s ‘ Elementary Geology,’ 1840, p. 283. 
