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states acting on the nervous centre, and thence on nerves of sense, 
or sensations produced through one set of nerves reacting on other 
nerves of the same character. The latter idea is manifestly the 
same as what in modern times has been termed the radiation of 
sensation. 
With respect to Whytt’s controversy with Haller, and the several 
papers published thereon, it referred to the dependence or non- 
dependence of irritability, now termed contractility, on nerves, — the 
former opinion being maintained by Whytt, the latter by Haller. 
This subject was largely experimented on by Whytt, whose mode of 
thinking gained many converts in his own time and in subsequent 
years. It has happened, however, that Haller’s views in this 
particular prevail at the present time, with this understanding, — that 
though the contractility of the organs concerned in the vegetative 
functions is not regarded as dependent on nerves, yet the organs of 
all such functions are believed to be very largely modified by an 
influence derived from nerves. 
As the Memoir itself is of considerable length, and is mainly 
devoted to the elucidation of the two works above referred to, what 
has just been said gives but an imperfect idea of the entire character 
of these principal works of Whytt. 
The Memoir concludes with some notice of his other papers, and 
in particular with a short view of his posthumous work on acute 
hydrocephalus, on which, in several particulars, he is an original 
authority. 
3. On a difficulty in the Theory of Bain. By James 
Dal m ahoy, Esq. 
The difficulty which the paper discusses is the paradoxical fact 
discovered by Dr Heberden, — namely, that if there be three exactly 
similar rain-gauges, and one of them be placed on the ground, the 
second on the roof of a neighbouring house, and the third on a still 
higher edifice, then, notwithstanding every variety in the posi- 
tions of these gauges as respects surrounding objects, and notwith- 
standing the prevalence of the opposite conditions of high wind and 
of absolute calm, it is observed that the lowest gauge receives more 
rain than the middle one, and the middle gauge more rain than 
the upper one. 
The paper endeavours to show the inadequacy of the explanations 
