I must confess I cannot see how _this Experiment_ can ever be made with the _nicety_ and _justness_ that is requisite, in order to _build_ upon it so _much_ as _these Gentlemen_ do. 'Tis hard to weigh _Earth_ in that _quantity_, or _Plants_ of the _size_ of those they mention, with any great _exactness_; or to _bake_ the Earth with that _accuracy_, as to reduce it _twice_ to just the _same Driness_. But I may wave all this; for though the _Experiment_ be never so easily practicable, and all the Accidents of it exactly as they set forth, yet nothing like what they _infer_ can possibly be concluded from it; unless _Water_, which they so plentifully bestow upon the _Plant_ in _this Experiment_, be _pure_, _homogeneous_, and not charged with any _terrestrial Mixture_; for if it be, the Plant after all may owe its _Growth_ and _Encrease_ intirely to _that_. Some _Waters_ are indeed so very _clear_ and _transparent_, that one would not easily suspect any _terrestrial Matter_ were latent in them; but they may be _highly saturated_ with such _Matter_, though the Eye be not presently able to descry or discern it. 'Tis true, _Earth_ is an _Opake Body_; but it may be so far dissolved, reduced to so extreme small Particles, and these so _diffused_ through the _watry Mass_, as not sensibly to impede _Vision_, or render the Water much the less _diaphanous_. _Silver_ is an _Opake_, and indeed a very _dense Body_; and yet, if perfectly _dissolved_ in _Spirit_ of _Nitre_, or _Aqua Fortis_, that is _rectified_ and thorowly _fine_, it does not _darken_ the _Menstruum_, or render it less _pellucid_ than before[5]. And other Instances there are, that oftentimes _great quantities_ of _Opake Matter_ are sustain'd in _Fluids_, without considerably striking the _Eye_, or being perceiv'd by it. So that were there _Water_ any where found so _pure_, that the quickest Eye could discover in it no _terrestrial Intermixture_; that would be far short of a _Proof_, that in reality there was _none_. But after all, even the _clearest Water_ is very far from being _pure_ and wholly _defecate_, in any part of the World that I can learn. For ours here, I have had an Opportunity of examining it over a good part of _England_; and cannot say I ever met with any, that, however fresh and newly taken out of the Spring, did not exhibit, even to the naked Eye, great numbers of exceeding small terrestrial Particles disseminated through all parts of it. Thicker and crasser Water exhibits them in still greater Plenty.