VI PEEFACE . 



remainder that of Sillig (Grotha, 1851-3), excepting in some 

 few instances, where, for reasons given in the Notes, it 

 has been deemed advisable to depart from it. The first 

 two Books, and portions of others, are the performance of 

 the late Dr. Bostock, who contemplated a translation of 

 the entire work; but, unfortunately for the interests of 

 science, he was not permitted to carry his design into 

 execution. 



Upwards of a hundred pages had been printed off before 

 the present Translator entered on his duties ; and as they 

 had not the advantage of Dr. Bostock's superintendence 

 through the press, some trifling oversights have occurred. 

 These are, for the most part, corrected in a short Appendix. 



