The Fourth Part.

have observ’d to adhere to the Receiver in the forme almost of a Parallelipipedon; and of the Volatile salt of humane blood (long digested before distillation, with spirit of Wine) I can shew you store of graines of that Figure which Geometricians call a Rhombus; though I dare not undertake that the Figures of these or other Saline Crystals (if I may so call Them) will be alwaies the same, whatever degree of Fire have been employ’d to force them up, or how hastily soever they have been made to convene in the spirits or liquors, in the lower part of which I have usually observ’d them after a while to shoot. And although, as I lately told You, I seldom found any Difference, as to Medical Vertues, in the fixt Salts of Divers Vegetables; and accordingly I have suspected that most of these volatile Salts, having so great a Resemblance in smell, in tast, and fugitiveness, differ but little, if at all, in their Medicinal properties: As indeed I have found them generally to agree in divers of them (as in their being somewhat Diaphoretick and very Deopilative; Yet I remember HelmontError vero per distillationem nobis monstrat etiam Spiritum salinum plane volatilem odore nequicquam ut nec gustu distinguibilem a spiritu Urinæ; In eo tamen essentialiter diversum, quod spiritus talis cruoris curat Epilepsiam, non autem Spiritus salis lotii. Helmont. Aura Vitalis. somewhere informes us, that there is this Difference betwixt the saline spirit of Urine and that of Mans blood, that the former will not cure the Epilepsy, but the Latter will. Of the Efficacy also of the Salt of Common Amber against the same Disease in Children, (for in Grown Persons it is not a specifick) I may elsewhere have an Occasion to Entertain You. And when I consider that to the obtaining of these Volatile Salts (especially that of Urine) there is not requisite such a Destructive Violence of the Fire, as there is to get those Salts that must be made by Incineration, I am the more invited to conclude, that they may differ from one another, and consequently recede from an Elementary Simplicity. And, if I could here shew You what Mr. Boyle has Observ’d, touching the Various Chymicall Distinctions of Salts; You would quickly discern, not only that Chymists do give themselves a strange Liberty to call Concretes Salts, that are