Volume 1

The chemical works of Caspar Neumann ... / abridged and methodized. With large additions, containing the later discoveries and improvements made in chemistry and the arts depending thereon by William Lewis.

  • Neumann, Caspar, 1683-1737.
Date:
1773
Catalogue details

Licence: Public Domain Mark

Credit: The chemical works of Caspar Neumann ... / abridged and methodized. With large additions, containing the later discoveries and improvements made in chemistry and the arts depending thereon by William Lewis. Source: Wellcome Collection.

    32/464 (page 12)
    Chalk, of the Chalk (If All the other Acids readily and totally diffolve it: four ounces of Spirit of Nitre took up one ounce; the fame quantity of Spirit of Salt, fix drachms ; and the fame quantity of diftilled V inegar, three drachms. The adtion of the nitrous Acid was accompanied with a confiderable frothing* but no heat or red fumes. Solutions of Chalk in the nitrous and marine Acids, are extremely bitter; thofe made in diftilled Vinegar are much lefs fo. None of them perfectly cryftallize ; nor, if infpiffated, do they long retain a dry form : how carefully foever they be exficcated by fire, they deliquiate again in the air, though one more readily than another. It has been faid, that Chalk forms with the Vitriolic Acid a perfect Alurn : it may in¬ deed be combined with that Acid into a cryftalline form, but the Cryftals prove extremely different, in tafte as well as in their other qualities, from thofe of Alum : the Aluminous Earth is a fubftance of a peculiar Kind, hitherto nowhere difcovered but in the Alum itfelf, (See Alum). Solution of Chalk in the nitrous Acid forms, on evaporation, a tenacious mafs' like Turpentine ; which exficcated, and calcined a little, proves luminous in the dark. This Phofphorus is ufually diftinguifhed by the name of its firft difco- verer, Baldum : it is called alfo Phofphorus Hermeticus, from its being kept in hermetically fealed glaffes to fecure it from the air. It differs from fome other Phofphori, in appearing in fome degree luminous, after (!) Chalk with the Vitriolic Acid.'] Chalk does not diffolve, or but in fmall quantity, in the Vitriolic acid, whether concentrated or diluted. Th is Acid has neverthelefs a very ItrOng affinity with Chalk 5 abforbing it from all the other Acids, and forfaking even Alcaline Salts to unite with it. If this Earth be difiolved in Spirit of Nitre, Spirit of Salt, or diftilled Vinegar, the addition either of the pure Vitriolic Acid, or of compound Salts containing it, renders the liquor inftantly milky or eurdly 5 the Chalk being now combined with that Acid into a concrete, not at all, or exceeding fparingly, diffoluble. If the Solution of Chalk be largely diluted with water before the addition of the Vitriolic Spirit, the liquor continues for a time'tranfparent: on Handing it be¬ comes wheyifh, and at length depofttes cryftalliform concretions, which are found to be true Selenitse or gypfeous Malles 5 being mdiftbluble in .Acids, calcining in veftels into Plafter, and in contact with the fuel into Quick-lime. 3