The nineteenth Experiment, contains ſeveral inſtances of producing Colours, without the alteration of any Hypoſtatical principle, by the Priſm, Bubbles, and Feathers ( from [242] to [245].)
The twentieth Experiment Of turning the Blew of Violets into a Red by Acid Salts, and to a Green by Alcalizate ([245], [246].) and the uſe of it for Inveſtigating the Nature of Salts ([247], [248].)
The one and twentieth Experiment, of the ſame Changes effected by the ſame means on the Blew Tinctures of Corn-flowers ([249], [250].) And ſome Reſtrictions to ſhew it not to be ſo general a propriety as one might imagine ([251].)
The twenty ſecond Experiment, of turning a Solution of Verdigreaſe into a Blew, with Alcalizate and Urinous Salts ([252], [253], [254].)
The twenty third Experiment, of taking away the Colour of Roſes with the Steams of Sulphur, and heightning them with the Steams Condens'd into Oyl of Sulphur per Campanam ([254], [255].)
The twenty fourth Experiment, of Tinging a great quantity of Liquor with a very little Ting'd Subſtance, Inſtanced in Cochineel (from [255] to [257].)
The twenty fifth Experiment, of the more general uſe of Alcalizate and Sulphureous Salts in the Tinctures of Vegetables, further Inſtanced in the Tincture of Privet Berries, and of the Flowers of Meſereon and Peaſe (from [257] to [259].) An Annotation, ſhewing that of the three Hypoſtatical principles, Salt according to Paracelſus is the moſt active about Colours (from [259] to [261].) Some things Precurſory premis'd to three ſeveral Inſtances next following, againſt the fore-mention'd Operations of Salts ([261], [262].)
The twenty ſixth Experiment, containing Trials with Acid and Sulphureous Salts on the Red Tinctures of Clove-july-flowers, Buckthorn Berries, Red-Roſes, Braſil, &c. ([262], [263].)
The twenty ſeventh Experiment, of the changes of the Colour of Jaſmin flowers, and Snow drops, by Alcalizate and Sulphureous Salts ([263], [264].)
The twenty eighth Experiment, of other differing Effects on Mary-golds, Prim-roſes, and freſh Madder ([265].) with an Admonition, that theſe Salts may have differing Effects in the changing of the tinctures of divers other Vegetables ([266], [267].)