550 MEMOIR OF 
In the state of weakness and suffering which succeeded this 
severe illness, Mr Tyrier was for a long time incapable of re- 
turning to his professional studies: but his mind was incapable 
of inactivity; and he turned willingly to those pursuits in na- 
tural history which had formed the amusement and the delight 
of his youth, and which are perhaps of all others the most suit- 
able to the grateful feelings of convalescence. 
Among the works with which he now amused himself, was 
the once celebrated treatise of Dr Dernam, entitled Physico- 
Theology. In perusing it again, with all the affecting associa- 
tions which the past .and the present afforded him, he could 
not but lament, that it was in some degree rendered obsolete, 
by the innumerable discoveries with which science has been 
enriched since its publication, and that its popularity among 
those to whom it might be most serviceable, was restrained by 
the number of Latin quotations which remained without a 
translation. It occurred to him that his hours of convalescence 
could not be better employed than in remedying these defects, 
and in thus extending the usefulness of a work of which he 
had himself felt the value. This pleasing and unfatiguing 
task he executed with his usual ardour, and prefixing to it a 
short but valuable dissertation on Final Causes, published it in 
the year 1799. 
Of this work, it is unnecessary for me to enter into any fur- 
ther detail; but I cannot omit a passage relating to it, which 
I find among Mr Tyrxer’s papers, and which marks distinctly 
the great principle by which his studies as well as his conduct 
were governed. 
“ Of all my literary labours, (says he,) that which affords me 
“ the most pleasure on reflection, is the edition which I pu- 
“ plished of Derham’s Physico-Theology. ‘The account of the 
“ Life and Writings of Dr Dzruam, with the short disser- 
“ tation 
