The Mind indeed is the first Principle of all Muscular Motion; but in such Cases as these, its Promptitude to Action or Habit being so great, it is in a manner surpriz’d, and cannot recover it self after the Spirits are with violent Force determin’d pursuant to the Representation of the _Species_. For, _as_ in the former State of Things a Man is said to act Rationally, _so_ this latter Case is call’d a _Perturbation of Mind_, that is, a _Delirium_; tho’ it is very manifest, that in reality the Defect is not in the _Rational_, but _Corporeal_ Part; such _Species_ being really presented to the Mind, upon which by the Order of our Constitution such Motions ought to follow in the Body. Thus, for Instance, if the Liquor of the Nerves is, without the Presence of any thing hurtful, put into a Motion like unto that which a painful Impression makes in it, the same Bodily Actions must insue as proceed from Fear, Anger, or the like Passion, determining the Spirits towards the Muscular Parts; and a By-stander, who sees no reason for such a Representation made to the Mind, will presently conclude that the Person thus acting acts without or besides his Reason, that is, is _Delirous_; especially if the Hurry and Confusion of the Spirits be such, that not only _one_, but _several_ different _Species_ be at the same time presented to the Mind; for a Man in this Case may act the Part of one Joyful, Angry, Timorous, or the like, without any appearing Reason, and all this almost in the same Moment of Time. In one Word, _Deliria_ are the _Dreams_ of those who are _Awake_; and _as these_ in Us _Sleeping_ are infinitely various and wonderfully Compounded, and all from the same common _Cause_, diversely pressing the Orifices of the Nerves, and thus making different _Repercussions_ of their Fluid; and _as_ we all know that this Confusion making the Representation of several _Species_ to the Mind, there do hereupon follow, tho’ the Body seem now at Rest and in perfect Repose, such Motions in the Organs as are usually the Effect of the Arbitrary Determination of the Spirits thither; _so_ We are now to enquire what Alteration of the Body made by this Venom, can be the Occasion of this Disorder and Tumult in the Nervous Fluid, which excites in the Party infected such surprizing, and almost contradictory, Representations. Most of the Symptoms of those who are bitten by the _Tarantula_ are at the first, that is, before they rise to a _Delirium_, plainly the same with those which the Bite of a Viper induces; without doubt therefore, as we have before observed of the common Spider, that it pierces the Flesh with its hooked _Forceps_, and at the same time instils from the _Proboscis_ in the Mouth a liquid Venom into the Wound; so the like _Claws_ in _This_ (of which I have taken the Figure (51) out of _P. Bonanni,_ very much magnified (52),) do serve to make Way for an active and penetrating Juice emitted from the same Part.