160 Neerology.—Dr. Wollaston. 
To Dr. Wollaston every part of science seemed equally familiar ; 
and of him it might perhaps be more truly said than of any philo- 
sopher who has preceded him, that “nil erat quod non tetigit, nil 
tetigit quod non ornavit.” Astronomy was one of his chief and fa- 
vorite pursuits—a taste inherited from his father, and cherished by | 
his intimacy with the late Astronomer Royal of Dublin (now. Bishop ~ 
of Cloyne) and the present Astronomer Royal of Greenwich—an in- 
timacy commenced in early youth at Cambridge, and maintained 
through life. Science is indebted to him for many ingenious and 
important speculations ; such are his papers published in the Philo- 
sophical Transactions, on horizontal refractions, and on the horizon- 
tal refraction and dip of the horizon, containing his curious and in- 
genious invention of the dip-sector. Among the most remarkable of 
his astronomical papers, however, is that on the finite extent of the 
atmosphere, which affords a striking instance of the advantages that 
may accrue to science by the union of remote branches of knowl- 
edge inthe same mind. The arguments brought forward in that 
paper in favor of the non-divisibility of matter in infinitum, from as- 
tronomical phenomena, carry with them at least every semblance of 
soundness, and afford a singular specimen of his acute and scrutiniz- 
ing habit of thought; while the almost miraculous delicacy and cu- 
rious felicity of his manipulation in the practical departments of sci- 
ence—that microscopic tact, which in a thousand instances led him, 
through routes impervious to grosser intellects, to the most striking, 
unexpected, and novel results—is there exemplified in a remarkable 
manner, in the minute and apparently insignificant apparatus with 
which he was enabled to verify his own views, under circumstances 
which would effectually baffle ordinary instruments and ordinary 
observers. 
The sister science of optics is even more indebted to Dr. Wollaston 
than astronomy. His verification of the Huygenian law of double 
refraction ; his investigation of the refractive and dispersive powers 
of bodies, as a separate branch of physical inquiry, on which the 
perfection of the achromatic telescope depends; his discovery of the 
dark lines in the spectrum, since independently observed, with more 
refined means, and in greater detail, by Fraunhofer; but chiefly, the 
ingenious and elegant method practised by him for perfecting 
adjustment of the triple achromatic object glass, give him the highest 
i ™ 40-Guimence in this department. The instrument on which 
he tried and perfected this mode of adjustment is now, through his 
‘berality, the property of this society. 
