The Description of the Poisonous _Fangs_, their Make, Articulation and Motion, as also of the Glands that separate the Yellowish Liquor, and the Bags that contain it; I shall give, together with some Anatomical Observations, at the End of this Discourse. This Venomous Juice it self is of so inconsiderable a quantity, that it is no more than one good _Drop_ that does the Execution; and for this reason Authors have contented themselves with Trials of the Bite upon several Animals, never Essaying to examine the Texture and Make of the Liquor it self; for which purpose I have oftentimes by holding a Viper advantageously, and inraging it till it struck out its Teeth, made it to bite upon somewhat solid, so as to void its Poison; which carefully putting upon a Glass Plate, I have with a Microscope, as nicely as I could, viewed its Parts and Composition. Upon the first Sight I could discover nothing but a Parcel of small Salts nimbly floating in the Liquor, but in a very short time the Appearance was changed, and these saline Particles were now shot out as it were into _Crystals_ of an incredible Tenuity and Sharpness, with something like Knots here and there, from which they seemed to proceed, so that the whole Texture did in a manner represent a _Spider’s Webb_, tho’ infinitely Finer, and more Minute; and yet withal so rigid were these pellucid _Spicula_, or _Darts_, that they remained unaltered upon my Glass for several Months (13). I have made several Trials with this _Juice_ in order to find out under what Tribe of Salts these Crystals are to be ranged; and not without some difficulty, by reason of the Minute Quantity of the Liquor, and the Hazard of Experiments of this Nature, have plainly seen that it does, as an _Acid_, turn the blue Tincture of _Heliotropium_ to a Red Colour. I did not succeed so well in mixing it with Syrup of Violets, and yet it did really seem to induce in this a _Reddish Hue_; but I am very certain it did not at all change it to a _Greenish_ Colour, as it would have done if any ways _Alcalious_. This may suffice in their own way of arguing, to convince those Gentlemen, who without the Assistance of any Experiments, meerly to serve an _Hypothesis_ which they have too fondly taken up, have with great Assurance told the World, that the Viperine Venom is an _Alcali_, and consequently to be cured by _Acid_ Remedies. But it is by far more easie to Spin out a false Notion into precarious Reasonings, than to make faithful Experiments, and fairly improve ’em by just and necessary Consequences.