A refutation of the remarks on the Institutes of experimental chemistry: in a letter addressed to the members of the Society for the Encouragement of Arts, Manufactures, and Commerce / [Robert Dossie].

  • Dossie, Robert, -1777
Date:
1760
Catalogue details

Licence: Public Domain Mark

Credit: A refutation of the remarks on the Institutes of experimental chemistry: in a letter addressed to the members of the Society for the Encouragement of Arts, Manufactures, and Commerce / [Robert Dossie]. Source: Wellcome Collection.

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    it is not in the leaft true with refped to the other. Is this the confequence of blunder: or the pradice of a mean artifice, effeded in this manner? They take two things, of which, one being true, and having been faid by me, is admitted to be fo; and mentioned there as if I had faid the con¬ trary; and the other, which, being alfo faid by me, is denied to be true againft the reality of the faft; and they couple them together in fuch man¬ ner, that nothing can be denied or affirmed of the whole propofition: from whence they confe- quently obtain a deception in both points, by making it ftem that I have aflerted what was falfe with regard to one; and not delivered what was true with reg-ard to the other. Another remarkable afiertion of two glaring falfities is in page 7 where it is faid to be “ de- monjirable that Prujjian blue is iron; and tl^at no Jidpbur of any kind is contained in animalsP As this, though the afiertion of one period, comprizes two very different propofitions, it is necelfary to confider them feparately. The firft, that Prujjian blue ts ironj may poffibly have the authority of fome French writer: and is therefore brought here in contradiftion to my pofition, that it is conftituted of the fixt fulphur of animal or vegetable fubftances, and that earth which is the bafis of alum. It is neverthelefs falfe, in fa6f,as may be colledled from the manner in which Pruffian blue may be produced. For though green vitriol, which contains iron, is ufed for themore advantageous preparation of thisTub' ftance as a pigment, yet it may be obtained from bloody