Experiment II
Make a ſtrong Infuſion of broken Galls in Fair Water, and having Filtred it into a clean Vial, add more of the ſame liquor to it, till you have made it ſomewhat Tranſparent, and ſufficiently diluted the Colour, for the credit of the Experiment, leſt otherwiſe the Darkneſs of the liquor might make it be objected, that ’twas already almoſt Ink; Into this Infuſion ſhake a convenient quantity of a Cleer, but very ſtrong Solution of Vitriol, and you ſhall immediately ſee the mixture turn Black almoſt like Ink, and ſuch a way of producing Blackneſs is vulgar enough; but if preſently after you doe upon this mixture drop a ſmall quantity of good oyl of Vitriol, and, by ſhaking the Vial diſperſe it nimbly through the two other liquors, you ſhall (if you perform your part well, and have employ’d oyl of Vitriol Cleer and Strong enough) ſee the Darkneſs of the liquor preſently begin to be diſcuſs’d, and grow pretty Cleer and Tranſparent, loſing its Inky Blackneſs, which you may again reſtore to it by the affuſion of a ſmall quantity of a very ſtrong Solution of Salt of Tartar. And though neither of theſe Atramentous liquors will ſeem other than very Pale Ink, if you write with a clean Pen dipt in them, yet that is common to them with ſome ſorts of Ink that prove very good when Dry, as I have alſo found, that when I made theſe carefully, what I wrote with either of them, eſpecially with the Former, would when throughly Dry grow Black enough not to appear bad Ink. This Experiment of taking away and reſtoring Blackneſs from and to the liquors, we have likewiſe tryed in Common Ink; but there it ſucceeds not ſo well, and but very ſlowly, by reaſon that the Gum wont to be employed in the making it, does by its Tenacity oppoſe the operations of the above mention’d Saline liquors. But to conſider Gum no more, what ſome kind of Præcipitation may have to do in the producing and deſtroying of Inks without it, I have elſewhere given you ſome occaſion and aſſiſtance to enquire; But I muſt not now ſtay to do ſo my ſelf, only I ſhall take notice to you, that though it be taken for granted that bodies will not be Præcipitated by Alcalizat Salts, that have not firſt been diſſolved in ſome Acid Menſtruums, yet I have found upon tryals, which my conjectures lead me to make on purpoſe, That divers Vegetables barely infus’d, or, but ſlightly decocted in common water, would, upon the affuſion of a Strong and Cleer Lixivium of Potaſhes, and much more of ſome other Præcipitating liquors that I ſometimes employ, afford good ſtore of a Crudled matter, ſuch as I have had in the Præcipitations of Vegetable ſubſtances, by the intervention of Acid things, and that this matter was eaſily ſeparable from the reſt of the liquor, being left behind by it in the Filtre; and in making the firſt Ink mention’d in this Experiment, I found that I could by Filtration ſeparate pretty ſtore of a very Black pulverable ſubſtance, that remain’d in the Filtre, and when the Ink was made Cleer again by the Oyl of Vitriol, the affuſion of diſſolv’d Sal Tartari ſeem’d but to Præcipitate, and thereby to Unite and render Conſpicuous the particles of the Black mixture that had before been diſpers’d into very Minute and ſingly Inviſible particles by the Inciſive and reſolving power of the highly Corroſive Oyl of Vitriol.
And to manifeſt, Pyrophilus, that Galls are not ſo requiſite as many ſuppoſe to the making Atramentous Liquors, we have ſometimes made the following Experiment, We took dryed Roſe leaves and Decocted them for a while in Fair Water, into two or three ſpoonfulls of this Decoction we ſhook a few drops of a ſtrong and well filtrated Solution of Vitriol (which perhaps had it been Green would have done as well) and immediately the mixture did turn Black, and when into this mixture preſently after it was made, we ſhook a juſt Proportion of Aqua Fortis, we turn’d it from a Black Ink to a deep Red one, which by the affuſion of a little Spirit of Urine may be reduc’d immediately to an Opacous and Blackiſh Colour. And in regard, Pyrophilus, that in the former Experiments, both the Infuſion of Galls, and the Decoction of Roſes, and the Solution of Copperis employ’d about them, are endow’d each of them with its own Colour, there may be a more noble Experiment of the ſudden production of Blackneſs made by the way mention’d in the Second Section of the Second Part of our Eſſays, for though upon the Confuſion of the two Liquors there mention’d, there do immediately emerge a very Black mixture, yet both the Infuſion of Orpiment and the Solution of Minium were before their being joyn’d together, Limpid and Colourleſs.