xii PREFACE. 
distinctive marks in the margin to those titles which relate to 
his own especial departments of scientific research. 
It only remains for me to deprecate criticism as to the many 
errors unavoidable in a work of this kind ;—a work of consi- 
derable difficulty in itself, and undertaken on my part for the 
Ray Society as a labour of love, in the midst of other avoca- 
tions. And when it is stated that the matter supplied to the 
printer was written in eight or nine different languages, and 
in a variety of handwritings, some of them very illegible, and 
replete with erasures and corrections, due credit will be given 
to Messrs. R. and J. E. Taylor for the manner in which the 
printing has been executed. 
H. E. STRICKLAND. 
Oxford, April 1848. 
