A plain instructor; or, A compendious view of several subjects divine and human. [Followed by] Remarks on knowledge, a lecture

Blue and red Sapphire, Corundum, and Emery, are composed of nearly the same elements.

Onyx, Chrysophrase, Carnelian, and Agate, are varieties of Chalcedony.

Amethyst is Violet Quartz; coloured by iron and Man

ganese.

The only important difference between Beryl and Emerald is in their colours.

Jasper only differs from Agate in a chemical view in containing more iron.]

Before I proceed to the two remaining subjects which I have to put before you, I must ask you to pause for a moment; for we are now standing as on the border of two wonderful kingdoms; that of Death and Inertness and Fixedness, and that of Life and Activity and Change. We have briefly surveyed in the two last chapters the Inorganic World: and if you form an intelligent view of it, from the mountain to the pebble, from the gross and palpable to the refined and invisible, you cannot but feel wonder and delight wherever you are.

But a still more interesting field is now to be entered upon, in which you are to see other combinations of elements: other bodies; other agencies: wonders more deep, and beauty more exquisite. Matter with its affinities-what a subject for our observation and thought! Matter with its affinities and with life-surely we may repeat our exclamation with peculiar emphasis. A grain of sand or a drop of water will please the reflecting mind: but how more intense is the pleasure, when it considers a blooming flower, a sportive insect, or a joyous animal!

Allow me to observe, that the knowledge of these kingdoms which benefits the mind and gives it real delight, is not to be gained by hasty views, by superficial notions, and by merely lodging any number of words in the memory: no; it is only

to be gained by that close, long, and patient thought, which leads you to the understanding of things. I wish you to be thinkers. Whether you study God's works or God's word, be Thinkers; plain, laborious, sound, and humble Thinkers; and then you will be, what you ought to be, soberminded persons; happy and useful.

Bear in mind, I beseech you, what I say; and daily pray to God, that by the Inspiration of His Holy Spirit you may always think those things that be good, and true, and right, whatever may be the subject before you, earthly or divine; and that by the merciful guiding of God you may order your conversation aright, as those who know their Creator, Redeemer, and Sanctifier; as those who are striving to live AS WISE AND THOUGHTFUL, AS TRUE AND FAITHFUL CHRISTIANS.