one parcel of sulphur, antimony, or vitriol, which they have found in others.  For, though they are bodies of the same species, having the same nominal essence, under the same name, yet do they often, upon severe ways of examination, betray qualities so different one from another, as to frustrate the expectation and labour of very wary chemists.  But if things were distinguished into species, according to their real essences, it would be as impossible to find different properties in any two individual substances of the same species, as it is to find different properties in two circles, or two equilateral triangles.  That is properly the essence to us, which determines every particular to this or that classis; or, which is the same thing, to this or that general name:  and what can that be else, but that abstract idea to which that name is annexed; and so has, in truth, a reference, not so much to the being of particular things, as to their general denominations?

9.  Not the real Essence, or texture of parts, which we know not.

Nor indeed can we rank and sort things, and consequently (which is the end of sorting) denominate them, by their real essences; because we know them not.  Our faculties carry us no further towards the knowledge and distinction of substances, than a collection of those sensible ideas which we observe in them; which, however made with the greatest diligence and exactness we are capable of, yet is more remote from the true internal constitution from which those qualities flow, than, as I said, a countryman’s idea is from the inward contrivance of that famous clock at Strasburg, whereof he only sees the outward figure and motions.  There is not so contemptible a plant or animal, that does not confound the most enlarged understanding.  Though the familiar use of things about us take off our wonder, yet it cures not our ignorance.  When we come to examine the stones we tread on, or the iron we daily handle, we presently find we know not their make; and can give no reason of the different qualities we find in them.  It is evident the internal constitution, whereon their properties depend, is unknown to us:  for to go no further than the grossest and most obvious we can imagine amongst them, What is that texture of parts, that real essence, that makes lead and antimony fusible, wood and stones not?  What makes lead and iron malleable, antimony and stones not?  And yet how infinitely these come short of the fine contrivances and inconceivable real essences of plants or animals, every one knows.  The workmanship of the all-wise and powerful God in the great fabric of the universe, and every part thereof, further exceeds the capacity and comprehension of the most inquisitive and intelligent man, than the best contrivance of the most ingenious man doth the conceptions of the most ignorant of rational creatures.  Therefore we in vain pretend to range things into sorts, and dispose