^{page 577 note *} On the other hand, by the middle of last century the mathematical naturalists of the Continent, after half a century of resistance to the Newtonian principles (which, both by them and by the English followers of Newton, were commonly supposed to mean the recognition of gravity as a force acting simply at a distance without mediation of intervening matter), had begun to become more “Newtonian” than Newton himself. On the 4th February 1744, Daniel Bernoulli wrote as follows to Euler, “Uebrigens glaube ich, “dass der Aether sowohl gravis versus solem, als die Luft versus terram “sey, und kann Ihnen nicht bergen, dass ich über diese Puncte ein völliger “Newtonianer bin, und verwundere ich mich, dass Sie den Principiis “cartesianis so lang adhäriren; es möchte wohl einige Passion vielleicht “mit unterlaufen. Hat Gott können eine animam, deren Natur uns unbe- “greiflich ist, erschaffen, so hat er auch können eine attractionem universalem “materæ imprimiren, wenn gleich solche attractio supra captum ist, da “hingegen die Principia Cartesiana allzeit contra captum etwas involviren.”

^{page 578 note *} An Inquiry concerning the Source of the Heat which is excited by Friction. By Count Rumford.—Philosophical Transactions, 1798.

^{page 578 note †} Vobis (Epicureis) minùs notum est, quemadmodum quidque dicatur. Vestra enim solùm legitis, vestra amatis; cæteros, causâ incognitâ, condemnatis. Cicéron, De natura Deorum, ii. 29.

^{page 581 note *} To render the sentence more easily read, I have substituted this number in place of the following words:—“le nombre de fois que le firmament contient le disque apparent du soleil.”

^{page 584 note *} De Causa gravitatis Redekeriana.

^{page 584 note †} Le Sage was remarkably scrupulous in giving full information regarding ll who preceded him in the development of any part of his theory.

^{page 585 note *} Le Sage estimated the velocity after collision to be two-thirds of the velocity before collision.

^{page 585 note †} Posthumous. “Traité de Physique Mecanique,” edited by Pierre Prévost. Geneva and Paris, 1818.

^{page 585 note ‡} Newton (Optics, Query, 30 Edn. 1721, p. 373) held that two equal and similar atoms, moving with equal velocities in contrary directions, come to rest when they strike one another. Le Sage held the same; and it seems that writers of last century understood this without qualification when they called atoms hard.

^{page 587 note *} Maxwell's “Elementary Treatise on Heat,” chap. xxii. Longman,1871.

^{page 589 note *} “Theory of magnetic induction in crystalline and non-crystalline sub“stances.”—Phil. Mag., March 1851. “Forces experienced by inductively “magnetised ferro-magnetic and dia-magnetic non-crystalline substances.”—Phil. Mag., Oct. 1850. “Reciprocal action of dia-magnetic particles.”—Phil. Mag., Dec. 1855; all to be found in a collection of reprinted and newly written papers on electrostatics and magnetism, nearly ready for publication, (Macmillan, 1872).