Vll

I have given the extracts from my papersnearly in the order in which they werepublished ; which will, I hope, both renderthe facts more intelligible, and shew thegradual progress of the enquiry: in whichevery step was furnished by experiment orinduction, in which nothing can be said tobe owing to accident, and in which themost simple and useful combination aroseout of the most complicated circum-stances.

The result of these labours will, I trust*be useful to the cause of science, by prov-ing that even the most apparently abstractphilosophical truths may be connected withapplications to the common wants and pur-poses of life.

The gratification of the love of knowledgeis delightful to every refined mind; but amuch higher motive is offered for indulgingin it, when that knowledge is felt to be