The eighteenth Experiment, Of several Compositions of Blew and Yellow which produce not a Green, and of the production of a Green by other Colours ([241], [242].)
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].)