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De Lac, the Geologist, 393 
John Andrew De Luc, F.R.S., aged 90. , That celebrated and 
indefatigable geologist has committed the result of his laborious 
and multifarious researches, unremittingly prosecuted for up- 
wards of fifty years, to numerous works which place him on a 
level with the most distinguished philosophers of this enlightened 
age. Having visited almost every part of Europe, in order to en- 
large his knowledge and increase his collection of facts by personal 
observations of geological phenomena, Mr. De Luc has thereby 
been enabled to demonstrate the comparatively small antiquity 
of our continents, and the difficulty of carrying back their origitt 
to a period more remote than that which the Mosaic chronology 
has assigned to the flood. It may also be observed, that Mr. De 
Luc has not only extended the limits of geology, and established 
fundamental points in that science, but has been a highly suc- 
cessful experimentalist in various branches of natural philosophy 
intimately connected with it, and in which he has made very 
valuable discoveries. ‘Those concerning the mode of action of 
the Galvanic pile are particularly interesting: he has ascertained 
that, in Volta’s pile, the chemical effects can be separated from 
the electrical ; and these last led that ingenious philosopher to - 
construct a new meteorological instrument, very desirable for ac- 
quiring a knowledge.of atmospherical phenomena, and which he 
exied the Electric Column. It is well known that Mr. De Luc 
was a strenuous opponent of the new chemical theory known by 
the name of Lavoisier’s. He has shown in his two “ Memoirs” 
on that theory, prefixed to his Introduction @ la Physique Ter- 
restre par les Fluides expansihles, that meteorological phzno- 
mena strongly militate against it; and, in general, that the hy- 
pothesis of the composition of water (the fundamental point in 
the theory) has maintained itself only by numerous other hypo- 
theses which are in contradiction with known facts. Mr. De 
Luc’s theories on evaporation, on the dew, on the formation of 
the clouds, on rain, &c., are grounded upon the most accurate 
experiments aud patient observation of the respective pheno- 
mena. 
Mr. De Lue was not less amiable as a man than he was emi- 
nent as a philosopher., To the powers of an understanding of 
the first order he united the most endearing qualities of the heart. 
The warmth of his feelings, and the habitual gentleness and ur= 
banity of his manners, were acmirably calculated to procure to 
him friends, and to retain them when gained. In the varied re- 
lations of life, as husband, father, master, friend, he exhibited 
the most edifying model of the social virtues. From the situa- 
tion he held as reader to the Queen, Mr. De Lue had for many 
years daily aceess to Her Majesty; and that his faithful services 
were justly appreciated, was rendered evident from the flattering 
-. ; testimonies 
