XK PREFACE. 
another System which had fixed its base in truth and reason, which had perfect Geo- 
graphical congruity, and undoubted priority of date; and which appeals to them still in a 
language they cannot misunderstand, if they will read their lesson in the very order in 
which the Author of Nature has recorded it. 
It may perhaps be objected to me that all or nearly all that has been stated in this 
Preface has appeared before in the Introduction to M*Coy’s Synopsis, or in the various Papers 
which have been printed in my name; especially in the Proceedings and Quarterly Journal 
of the Geological Society, or in the Philosophical Magazine and Annals of Philosophy. But 
certainly they were never printed before in a form so connected and historical as in the 
statements of this Preface. With the solemnity becoming my old age and a conviction, 
forced upon me by my infirmities, that I shall never again be able to address the Public 
upon any subject connected with the scientific labours of my former life, I dare to affirm that 
the Geological Society had not a more true-hearted and loyal member than myself. The 
stigma fixed upon me by the Council of the Geological Society was the greatest sorrow 
of my old age. I never endeavoured to deprive any brother Geologist of what was his 
due, nor did I claim for myself any scrap of knowledge for which I could not make good 
my title. My Maps and Sections literally were public property, Prof. Phillips had the use 
of my field-work in Cumberland, when he was preparing one of his Volumes and Maps 
for Publication; and Mr Greenough had my Papers and Maps in his possession for weeks 
together, and on several successive occasions. Such details may seem but ill fitted for 
the pages of this Preface; but I write as one who has endured, and is still enduring, the 
unmerited censure of a scientific body; and who for the last time is writing in defence 
of his conduct as an author. 
At what time the grand mistakes in the fundamental Sections of the Silurian System 
were first discovered, and by whom first published, is to me still unknown. I gradually 
made out the mistakes for myself, after clinging to the first typical Lower Silurian Groups 
longer than I ought to have done. I never was in the real confidence of my old com- 
panion and fellow-labourer after we parted in 1834 at the quarry, in the Bala Limestone, 
at the Western base of the Northern Berwyns (supra, p. xix). 
Conclusion. 
Having finished all that can with propriety be called a Preface to the following Cata- 
logue, I will endeavour to address a few words to the resident members of the University. 
I can never again hope to address the Public at the length I have done in this 
Preface; for I feel the infirmities of old age, yearly, I might almost say daily, pressing 
