62 SECTIONAL ADDRESSES 
workers right up to the beginning of this century ; they took the view that 
evidence must be collected, and it mattered little whether they adopted 
the theory of evolution or not. 
The culmination of this work in Britain, for the time being, came with 
the publication of Lindley and Hutton’s Fossil Flora of Great Britain in 
1837; but an additional series of figures, prepared under their super- 
vision, was published in 1877 under the editorship of Prof. G. A. Lebour. 
While not ranking so high as Brongniart’s Histoire des végétaux fossiles, this 
Fossil Flora is a most important publication, and is the last large work on 
incrustations published in Britain until practically recent times. 
A New TECHNIQUE FOR STUDYING FossIL PLANTS. 
But while Artis, Martius, Sternberg and, in particular, Brongniart, and 
Lindley and Hutton were establishing the classification and description 
of incrustations of plants, a new method had been devised for the investi- 
gation of the internal structure of certain specimens, by the examination 
of thin sections made from them. I have already referred to the useless- 
ness of many of Knorr and Walch’s beautiful plates, because of the want 
of details of structure, and Hooke’s microscopical examinations had also 
borne no fruit, but when Henry Witham published his two works }* the atten- 
tion of the scientific world was attracted to the possibility and importance 
of studying the internal structure of fossil plants. The history of the 
method of making thin sections of fossil plants I have already placed before 
this Section,2® and there drew attention to the controversy that arose 
between Nicol and others, as to who originated the method. Jameson, 
writing as editor of the Edinburgh New Philosophical fournal in 1834, 
says he had long known the method, and had advocated its use to geologists. 
Nicol in the same journal claims he had used the method for fifteen years, 
and there is no doubt that Nicol introduced improvements in it ; but there 
also seems little doubt that lapidaries had used an essentially similar 
method prior to Nicol. Sprengel also had published, in 1828, a work on 
fossil plants for which he employed sections. ‘There is no doubt, how- 
ever, that it was Witham’s work that showed the importance of the method. 
(Henry Witham was one of the first members of the British Association, 
and was one of the twelve constituting the sub-committee on Geology 
and Geography at York in 1831.) * 
The advent of the new technique had more than one consequence. It 
divided the study of fossil plants into two sections, one biological and the 
other stratigraphical, but it also led indirectly to what was probably the 
greatest advance ever made in Petrology. ‘The story is too important to 
be omitted from this address, although only in a secondary sense can we 
consider it one of the influences of the study of fossil plants on geology. 
19 Observations of Fossil Vegetables, 1831. Inteynal Structure of Fossil Vege- 
tables, 1833. 
20 British Association, Oxford Meeting, 1926, Section C, p. 348. 
21 Sprengel, Commentatio de Psarolithis ligni fossilis genere, 1828. 
2a Gregory, Pres. Address, Section C, British Association, Centenary Meeting, 
London, 1931. ; 
