The early history of chlorine / papers by Carl Wilhelm Scheele ... [and others].

  • Carl Wilhelm Scheele
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: The early history of chlorine / papers by Carl Wilhelm Scheele ... [and others]. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    19/58 (page 15)
    has also the property of combining with dephlogisticatcd marine acid, and dissolves in it in fairly considerable quantity; it is precipitated from it by all the alkalies, and even by lime water; which proves that lime combines with this liquid more strongly than effervescent calcareous earth does. We can therefore, as it seems to me, regard dephlogis- ticatcd marine acid as almost entirely deprived of acidity. ScHEELE and Bergman were unable to recognise this essential property, as in the process which they employed the water of the vessels in which they received the gas could contain only a very small portion of dephlogisticatcd marine acid, mixed with a portion of marine acid which always passes over in the distillation; in my apparatus this portion of marine acid is retained in the first bottle, which I leave empty, and which it is well to surround with ice or cold water. When the operation is not made with sufficient care a little marine acid passes even into the first bottle which is filled with water; this accident can be easily recognised by pouring into the liquid some solution of effervescing fixed alkali; if any bubbles are seen to be disengaged this is a proof that it contains some marine acid, for it should not produce any effervescence. In a retort at the pneumato-chemical apparatus, I boiled a mixture of mineral alkali and dephlogisticatcd marine acid; much gas was disengaged, of which a great part was fixed air, and the other part at first atmospheric air and then air purer than this, but the last portions were hardly anything but fixed air. With lime there is no fixed air disengaged, but atmospheric air which gradually approaches to vital air, and finally a little very pure vital air. The fixed air of the first experiment is thus furnished by the alkali, as it is in the effervescences, the atmospheric air is due to the space which I left empty in the apparatus, and the vital air to the dephlogisticatcd marine acid.