The great bulk which the Synonymy of botany and of mineralogy have attained, shows us that this maxim has not been universally attended to. In these cases, however, the multiplication of different names for the same kind of object has arisen in general from ignorance of the identity of it under different circumstances, or from the want of a system which might assign to it its proper place. But there are other instances, in which the multiplication of names has arisen not from defect, but from excess, of the spirit of system. The love which speculative men bear towards symmetry and completeness is constantly at work, to make them create systems of classification more regular and more perfect than can be verified by the facts: and as good systems are closely connected with a good nomenclature, systems thus erroneous and superfluous lead to a nomenclature which is prejudicial to science. For although such a nomenclature is finally expelled, when it is found not to aid us in expressing the true laws of nature, it may obtain some temporary sway, during which, and even afterwards, it may be a source of much confusion. We have a conspicuous example of such a result in the geological nomenclature of Werner and his school. Thus it was assumed, in Werner's system, that his _First_, _Second_, and _Third Flötz Limestone_, his _Old_ and _New Red Sandstone_, were universal formations; and geologists looked upon it as their business to detect these strata in other countries. Names were thus assigned to the rocks of various parts of Europe, which created immense perplexity before they were again ejected. The geological terms which now prevail, for {292} instance, those of Smith, are for the most part not systematic, but are borrowed from accidents, as localities, or popular names; as _Oxford Clay_ and _Cornbrash_; and hence they are not liable to be thrust out on a change of system. On the other hand we do not find sufficient reason to accept the system of names of strata proposed by Mr. Conybeare in the _Introduction to the Geology of England and Wales_, according to which the _Carboniferous Rocks_ are the _Medial Order_,--having above them the _Supermedial Order_ (_New Red Sand_, _Oolites_ and _Chalk_), and above these the _Superior Order_ (_Tertiary Rocks_); and again,--having below, the _Submedial Order_ (the _Transition Rocks_), and the _Inferior Order_ (_Mica Slate_, _Gneiss_, _Granite_). For though these names have long been proposed, it does not appear that they are useful in enunciating geological truths. We may, it would seem, pronounce the same judgment respecting the system of geological names proposed by M. Alexander Brongniart, in his _Tableau des Terrains qui composent l'écorce du Globe_. He divides these strata into nine classes, which he terms _Terrains Alluviens_, _Lysiens_, _Pyrogenes_, _Clysmiens_, _Yzemiens_, _Hemilysiens_, _Agalysiens_, _Plutoniques_, _Vulcaniques_. These