The principle of a mineralogical nomenclature determined by the place of the species in the system, has been recognized by Mr. Beudant as well as Mr. Mohs. The former writer has proposed that we should say _Carbonate Calcaire_, _Carbonate Witherite_, _Sulphate Couperose_, _Silicate Stilbite_, _Silicate Chabasie_, and so on. But these are names in which the part added for the sake of the system, is not incorporated with the common name, and would hardly make its way into common use. We have already noticed Mr. Mohs's designations for two of the Systems of Crystallization, the _Pyramidal_ and the _Prismatic_, as not characteristic. If it were thought advisable to reform such a defect, this might be done by calling them the _Square Pyramidal_ and the _Oblong Prismatic_, which terms, while they expressed the real distinction of the systems, would be intelligible at once to those acquainted with the Mohsian terminology. I will mention another suggestion respecting the introduction of an improvement in scientific language. The term _Depolarization_ was introduced, because it was believed that the effect of certain crystals, when polarized light was incident upon them in certain positions, was to destroy the peculiarity which polarization had produced. But it is now well known, that the effect of the second crystal in general is to divide the polarized ray of light into two rays, polarized in different planes. Still this effect is often spoken of as _Depolarization_, no better term having been yet devised. I have proposed and used the term _Dipolarization_, {345} which well expresses what takes place, and so nearly resembles the elder word, that it must sound familiar to those already acquainted with writings on this subject. I may mention one term in another department of literature which it appears desirable to reform in the same manner. The theory of the Fine Arts, or the philosophy which speculates concerning what is beautiful in painting, sculpture or architecture, and other arts, often requires to be spoken of in a single word. Baumgarten and other German writers have termed this province of speculation _Æsthetics_; αἰσθάνεσθαι, _to perceive_, being a word which appeared to them fit to designate the perception of beauty in particular. Since, however, _æsthetics_ would naturally denote the Doctrine of Perception in general; since this Doctrine requires a name; since the term _æsthetics_ has actually been applied to it by other German writers (as Kant); and since the essential point in the philosophy now spoken of is that it attends to Beauty;--it appears desirable to change this name. In pursuance of the maxim now before us, I should propose the term _Callæsthetics_, or rather (in agreement with what was said in page 338) _Callæsthetic_, the science of the perception of beauty. {{346}} FURTHER ILLUSTRATIONS OF THE APHORISMS ON SCIENTIFIC LANGUAGE, FROM THE RECENT COURSE OF SCIENCES. 1. BOTANY.