A treatise on pharmacy for students and pharmacists / by Charles Caspari, Jr.

  • Caspari, Charles, 1850-1917.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on pharmacy for students and pharmacists / by Charles Caspari, Jr. Source: Wellcome Collection.

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    ward and escapes through the gauze A. For a stronger heat the gas and air mixed are lighted above the wire gauze, and a steady, smoke- less, blue flame is thus obtained. As any rubber tubing attached to D is apt to become very hot, it should either be wrapped with a small wet cotton cloth, dipping in water, or, what is still better, about eight inches of gas-pipe should be permanently attached to D, to which the rubber supply-tube may be secured when wanted. Fig. 49 represents a convenient foot-blower for use with any gas furnace requir- ing a strong supply of air; the rubber disk is well protected by netting. For small operations at the dispensing counter, Bunsen burners are usually employed, which are so constructed that a small supply of gas is made to yield a strong heat by admixture with air, whereby perfect combustion is effected. One drawback to the majority of Bunsen burners in the market is the tendency to light back—that is, when the flame is reduced, it is apt to recede and ignite the gas at the pinhole orifice in the tube; the most effectual method of overcoming this difficulty is to contract the orifice of the tube and introduce a gauze diaphragm into it near the top, which, how- ever, reduces the heating power of the flame. Among the large variety of Bunsen burners sold, a few have been found specially adapted to the use of the pharmacist, and are here illustrated. Fig. 50 represents a low form of burner, 3 inches high, made in Fig. 50. Fig. 51. the aid of a contracted brass cap. The Acme safety burner. the flame can be turned down quite low without receding. When it is desired to distribute the flame, the brass crown shown in the Cut should be attached, after removal of the brass cap; the crown, being provided with three supports, does away with the necessity for a tripod. The burner is made by Bullock & Crenshaw, of Philadelphia, and will be found very