Public health laboratory work / by Henry R. Kenwood.

  • Henry Richard Kenwood
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Public health laboratory work / by Henry R. Kenwood. Source: Wellcome Collection.

    35/502 (page 9)
    The eye must always be on a level with the upper surface of the liquid when a reading is made. The buretta just holds lo c.c. of water, if at a temperature of about 60 deg. F., the water weighs 9-99 grammes. Similarly with a measuring flask (fig. 13), the graduation is correct if the 100 c.c. of water at about 60 deg. F. weigh 99-9 grammes. 16. Four graduated glass-flasks (measuring flasks) marked respectively at the height to which i, j/^ and of a litre of water will stand. Fig. 13 shows one such flask. 17. Twelve Nessler glasses, four of which are shown in fig. 28. 18. A dozen test-tubes, with stand for same, and a test- tube cleaner and holder (fig. 14). 19. A glass pipette. Pipettes should not be blown out, but allowed to drain, and the drop at the dehvery end removed by touching the side of the vessel into which the contents of the pipette are emptied. 20. Two four-footed iron stands. 21. Two iron tripods (fig. 15). 22. Triangles of iron-wire lined with pipe-clay (fig. 16). 23. Stout fine wire gauze, cut about four inches square. 24. A pair of small crucible tongs (fig. 17), which may, with advantage, be platinum pointed. Fig. 14.—Test-tube stand, cleaner and holder.