Page:Proceedings of the Royal Society of London Vol 1.djvu/273

Rh lies, or acids, produced very little effect, although they are better con- doctors.

Lastly, some general applications of these singular facts are pointed out by Mr. Davy; such, for instance, as the application of electricity to the analysis of animal and vegetable substances. Muscular ﬁbre being electriﬁed for some time, became dry and hard; and it left, upon incineration, no saline matter. Potash, soda, ammonia, lime, and oxide of iron, were collected on the negative side ; and the sul- phuric, nitric, muriatic, phosphoric, and acetous acids, on the posi- tive. Laurel-leaf was rendered brown and parched; green colouring matter, with resin, alkali, and lime, appeared in the negative vessel, and prussic acid in the positive.

By using charcoal and plumbago, or charcoal and iron, as the ex- citing powers, along with neutro-saline solutions, large quantities of acids and alkalies might be procured with little trouble or expense.

It is very probable that many mineral formations have been mate- rially inﬂuenced or even occasioned by the agency of the electricity; and the electrical power of transference may thus be applied to the explanation of the principal points in geology.

The Professor observes, that Sir Isaac Newton was the ﬁrst ma- thematician who endeavoured to estimate the quantity of the pre- cession from the attractive inﬂuence of the sun and moon on the spheroidal ﬁgure of the earth. His investigations relating to this subject evince the same transcendent abilities that are displayed in other parts of his Principia; but it is admitted, that, from a mistake in his process, his conclusion is erroneous.

The investigations of other mathematicians in attempting the solu- tion of the same problem are arranged by the author under three general heads. The ﬁrst arrive at wrong conclusions, in consequence of mistake in some part of their proceedings; the second obtain just conclusions, but rendered so by balance of opposite errors; the third approach as near the truth as the nature of the subject will admit, but, in the author‘s estimation, are liable to the charge of obscurity and perplexity.

The defects in all their investigations Professor Robertson ascribes to the same cause—the uncultivated state of the doctrine of com- pound rotatory motion.

The author‘s endeavours are, consequently, ﬁrst directed to the investigation of the principles of compound rotatory motion from principles which he considers clear and unexceptionable.

He next proceeds to calculate the disturbing solar force on the spheroidal ﬁgure of the earth, and thence the angular velocity which it produces.

The quantity of annual precession is then computed; and, lastly,