No quality is more inconsistent with the character of a stone than flexibility. A flexible stone, therefore, presents an idea which naturally strikes us with surprise. For though among mineral bodies, we find flexible substances of the stony kind, such as mica, mountain leather, and amianthus, these minerals owe their flexibility, either to their thinness, or to the fibrous structure of their parts. Therefore, when a stone of any considerable thickness is said to have flexibility, we are led to think that here is something very extraordinary; and we wish to know upon what depends that quality, nowise proper to a stone.

The restoration of the ancient books of geometry would have been impossible, without the coincidence of two circumstances, of which, though the one is purely accidental, the other is essentially connected with the nature of the mathematical sciences. The first of these circumstances is the preservation of a short abstract of those books, drawn up by Pappus Alexandrinus, together with a series of such lemmata, as he judged useful to facilitate the study of them. The second is, the necessary connection that takes place among the objects of every mathematical work, which, by excluding whatever is arbitrary, makes it possible to determine the whole course of an investigation, when only a few points in it are known. From the union of these circumstances, mathematics has enjoyed an advantage of which no other branch of knowledge can partake; and while the critic or the historian has only been able to lament the fate of those books of Livy and Tacitus which are lost, the geometer has had the high satisfaction to behold the works of Euclid and Apollonius reviving under his hands.

Words that are precisely equivalent are rarely, if at all, to be met with in any language. Those properly called synonymous, exhibit one leading circumstance in which they all agree, and one or more accessory circumstances in which they differ. When the point of their general coincidence, and the grounds of their particular diversities, are clearly ascertained, it is then in the power of the writer to use them with propriety. By the assistance of the grammarian, he knows which to adopt and which to reject, and can reconcile embellishment with accuracy and precision.

Dear Sir,

The earthquakes which have lately taken place at Comrie and its neighbourhood, are certainly very deserving of attention. I shall therefore cheerfully comply with your request, and give you as particular a description as I can of such of them as have been most remarkable. To give a particular account of all the noises or concussions which, during the last half-year, have been heard or felt at Comrie, and within a short distance to the north, east and west of that village, is beyond my power, and would indeed be of little use.

This monster, of which the mother was delivered by Mr Thomas Anderson, surgeon in Leith, after the birth of a complete child at the full time, had its proper membranes and a placenta, with a short umbilical cord.

The following parts were wanting in it; to wit, the bones of the head; the brain, with the organs of sight, hearing, smell and taste; the neck; about one half of the ribs; the larynx, trachea and lungs; the heart; the pharynx, œsophagus and stomach, with all the small intestines, except the end of the ilium; the anus; the liver, spleen, pancreas and omenta; the renal glands; terminations of the ureters; the middle part of the urethra; the right testicle; both arms; both patellæ; with several of the bones of the feet and toes.

Dear Sir,

Part of my promise has been accomplished in a former letter, in which I gave you the fullest account I could of the springs of boiling water that rise in the valley of Rykum. It now remains for me to send you a description of those we visited in the neighbourhood of Haukadal.

These last are the most remarkable in the island, and the eruptions of water from some of them so astonishing, that I doubt whether any adequate idea of their effect can be given by description. Abler pens than mine might fail probably in attempting to do justice to such wonderful phenomena. The objects, however, are so highly interesting in themselves, that even the simplest narrative that can be given of them will be read with more than ordinary attention.

In some other dissertations, I have endeavoured to investigate the original country of the Iones, Dores, Æoles and Achæi or Achivi; and have, I hope, shewed, that none of these tribes were aborigines of Greece. In this paper, I shall trace the origin of the Hellenes, a people who, in process of time, be came so considerable, that all the other septs and petty clan ships of that nation were proud of being called by that venerable name.

On the 3d of November last, Sir James Hall and Dr Rutherford asked me to repeat with them some experiments on what has been called Animal Electricity, which were first performed by Dr Galvani, Professor of Anatomy at Bologna, and of which an account had been communicated by Mr Seguin of Paris to Dr Black, in a letter dated Paris, 3d August.

Since reading the paper upon the theory of the earth, I have been employed in examining many parts of this country, in order to enquire into the natural history of granite. In this undertaking, I have succeeded beyond my most flattering expectations; and I am now to communicate to this Society the result of my observations.

In the paper just referred to, it was maintained, from many different arguments, that all the solid strata of the earth had been consolidated by means of subterraneous heat, softening the hard materials of those bodies; and that in many places, those consolidated strata had been broken and invaded by huge masses of fluid matter similar to lava, but, for the most part, perfectly distinguishable from it. Granite also was considered there as a body which had been certainly consolidated by heat; and which had, at least in some parts, been in the state of perfect fusion, and certain specimens were produced, from which I drew an argument in support of this conclusion.

Dear Sir,

I have been prevented hitherto, by various occupations, from acquitting myself of a promise you received from me, (I am ashamed to think how long a time since), that I would send you an account of the hot springs in Iceland, from whence the water was brought which you have lately analysed. I have trusted you would excuse a delay not altogether voluntary. It will be now my endeavour to gratify your curiosity as far as I am able; and to acquaint you with every particular, as well concerning the springs as the country near them, which I think you may find in the least interesting.