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abreast of the most important advances in medical science and 
speculation on the Continent. He translated Prochasta’s Treatise 
on the Nervous System and Unger’s Physiology. His own con- 
tributions to various branches of medical science were many, and 
most of great value. Besides numerous papers in the medical 
journals and in the transactions of learned societies, he published a 
Treatise on the Nervous Diseases of Women, in which he first de- 
veloped his views as to the scientific data of unconscious and in- 
voluntary brain function, and explained thereby the phenomena 
of mesmerism, dreaming, and insanity. The views advanced in 
this work he afterwards extended and completed as a system of 
Practical Philosophy, in a work in two volumes, entitled “ Mind 
and Brain, or the Correlation of Consciousness and Organisation,” 
of which the first edition appeared in 18G0 and the second in 1869. 
He also devoted much attention to the subject of epidemiology, 
and his papers on this and on questions of sanitary reform contri- 
buted much to turn attention to the important matter of public 
health, and to direct to the use of measures best fitted to secure and 
promote it. 
The natural bent of Dr Laycock’s mind was towards speculation 
and theory; but he had what many theorists and speculative thinkers 
have not, a capacity of minute observation and a patience of details 
which have enabled him to give to his writings a value and im- 
portance independent of the theories which they are intended to 
advocate. As to the soundness of these theories there may be, and I 
presume are, differences of opinion, but there can be but one 
opinion as to the conscientious carefulness and exactitude of his 
observations, and as to the value of the facts which he has collected 
and described. His doctrine concerning the reflex function of the 
brain is now, I believe, universally recognised by physiologists, and 
its importance both in a scientific and a practical relation acknow- 
ledged to be great. To the subject of mental disease Dr Laycock 
devoted much attention ; and he did not a little to advance the 
science of mental pathology, and thereby to place on a firmer basis 
the theory of the treatment of the insane. As a professor his aim 
was not merely to communicate knowledge to his students, but still 
more to awaken them to thought, to stimulate them to inquiry, and 
to urge them to use their faculties in the independent pursuit of 
