There is another class of rocky substances which obey no settled laws, and, therefore, are noticed here in an appendix: _They are rocks and substances of evident igneous origin_: as _basalt_, _obsidium_, _lavas of all textures_, and _trap_ rocks _frequently_, perhaps generally. These have one common origin: they are also of similar composition generally; and in this approach the composition of primitive rocks. They have been evidently _ejected from the bowels of the earth in a melted state_. They are found in almost all countries; and in some cases form mountains, and cover the surfaces of large districts to an astonishing depth: as in the north of Ireland, more than 500 feet thick, and over an area of 800 square miles. (URE.) Being _protruded_ from beneath in a melted state they are found injected through the superincumbent rocks in _shafts_ or _veins_ of various sizes, from several inches to several feet. Sometimes being unable to rend the solid rocks above they are injected _between their strata_. They are generally somewhat crystalline in structure, because deposited on the same principles as granite, when undisturbed. From their _position_, _superficial extent_, and _quantity_, we infer they are the products of all ages, and of immense igneous action, seated at an unknown distance beneath the surface of the earth. Hence we may have some idea of the vast amount of igneous action which operated in the early ages of our planet. It must have been violently shaken from the centre to the surface.] We may well ask, in the language of a German philosopher, Who can enumerate all the blessings which the vegetable kingdom affords? It is at least manifest that all the arrangements of Providence, in this respect, have for their grand object the advantage of the creatures. God has provided for the wants of each individual. He has assigned to each that plant, which is most proper for its nourishment and support. There is not a plant on the earth, but what has its particular destination and use. What sentiments of veneration and gratitude should we feel, at the sight of lawns, gardens, fields, and meadows! Here his beneficent care has collected all that is necessary for the comfort and preservation of the inhabitants of the earth. Here, oh God! thou openest thy hand, and satisfiest the desire of every living creature! Here every herb, ear of corn, flower, and tree, proclaims thy goodness! How closely might our modern geologists walk with God, if, like a Boyle, and a Ray, every new discovery led them to an increasing admiration of Divine wisdom and omnipotent power![103] for “Philosophy, baptiz’d In the pure fountain of eternal love, Has eyes indeed; and viewing all she sees As meant to indicate a God to man, Gives him his praise, and forfeits not her own.”