The antiquity and authenticity of the books which compose the sacred canon,—the fulfilment of its prophecies,—the miraculous works of its founder,—his death and resurrection, have been demonstrated to all who are capable of appreciating the force of historical evidence; and in the poetical and prose compositions of the inspired authors we discover a system of doctrine and a code of morality traced in characters as distinct and legible as the most unerring truths in the material world. False systems of religion have indeed been deduced from the sacred record,—as false systems of the universe have sprung from the study of the book of nature,—but the very prevalence of a false system proves the existence of one that is true; and though the two classes of facts necessarily depend on different kinds of evidence, yet we scruple not to say that the Copernican system is not more demonstrably true than the system of theological truth contained in the Bible. If men of high powers, then, are still found, who are insensible to the evidence which sustains the system of the universe, need we wonder that there are others whose minds are shut against the effulgent evidence which intrenches the strongholds of our faith.

If such, then, is the character of the Christian faith, we need not be surprised that it was embraced and expounded by such a genius as Sir Isaac Newton. Cherishing its doctrines, and leaning on its promises, he felt it his duty, as it was his pleasure, to apply to it that intellectual strength which had successfully surmounted the difficulties of the material universe. The fame which that success procured him he could not but feel to be the breath of popular applause, which administered only to his personal feelings; but the investigation of the sacred mysteries, while it prepared his own mind for its final destiny, was calculated to promote the spiritual interests of thousands. This noble impulse he did not hesitate to obey, and by thus uniting philosophy with religion, he dissolved the league which genius had formed with skepticism, and added to the cloud of witnesses the brightest name of ancient or of modern times.

CHAPTER XVII.

The minor Discoveries and Inventions of Newton—His Researches on Heat—On Fire and Flame—On Elective Attraction—On the Structure of Bodies—His supposed Attachment to Alchymy—His Hypothesis respecting Ether as the Cause of Light and Gravity—On the Excitation of Electricity in Glass—His Reflecting Sextant invented before 1700—His Reflecting Microscope—His Prismatic Reflector as a Substitute for the small Speculum of Reflecting Telescopes—His Method of varying the Magnifying Power of Newtonian Telescopes—His Experiments on Impressions on the Retina.

In the preceding chapters we have given an account of the principal labours of Sir Isaac Newton; but there still remain to be noticed several of his minor discoveries and inventions, which could not properly be introduced under any general head.

The most important of these, perhaps, are his chymical researches, which he seems to have pursued with more or less diligence from the time when he first witnessed the practical operations of chymistry during his residence at the apothecary’s at Grantham. His first chymical experiments were probably made on the alloys of metals, for the purpose of obtaining a good metallic composition for the specula of reflecting telescopes. In his paper on thin plates he treats of the combinations of solids and fluids; but he enters more largely on these and other subjects in the queries published at the end of his Optics.

One of his most important chymical papers is his Tabula quantitatum et graduum caloris, which was published in the Philosophical Transactions. This short paper contains a comparative scale of temperature from that of melting ice to that of a small kitchen coal-fire. The following are the principal points of the scale, the intermediate degrees of heat having been determined with great care.

Degrees
of Heat.		Equal Parts
of Heat.
0  0Freezing point of water.
1 12Blood-heat.
2 24Heat of melting wax.
3 48Melting point of equal parts of tin and bismuth.
4 96Melting point of lead.
5192Heat of a small coal-fire.