An introduction to the study of seaweeds / by George Murray.

  • Murray, George (George Robert Milne), 1858-
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of seaweeds / by George Murray. Source: Wellcome Collection.

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    alcohol, to remove as much air as possible. It should then be transferred to salt and water, and permitted to remain in it. A drop or two of glycerine should be added, and the process may be hastened by gently heating, not boiling. The most successful specimens are those that have been kept at about 90° F. for several hours. Material so treated may then be preserved in spirit (at first weak, and gradually strengthened). Living specimens to be preserved in spirit should be first treated with picric acid. A saturated solu- tion of picric acid in sea-water should be made and subsequently diluted with three or four times its volume of sea-water. The specimens should be im- mersed in it from a quarter of an hour to two hours, according to size and density; then washed in sea-water and placed first into weak spirit, and by degrees into stronger spirit. Specimens vary greatly as to the result of treatment by picric acid. To ob- tain thorough fixation of the contents of such Algae as Valonia (Fig. 46) it is necessary to immerse them for several hours in the saturated solution itself. For mounting microscope slides of seaweeds the best medium is clear glycerine jelly, which has the advantage of being easily manipulated. The examin- ation of Algae encrusted with carbonate of lime, such as the stony corallines, is facilitated by the use of Perenyi's decalcifying fluid (4 vols. 10 per cent, nitric acid, 3 vols. absolute alcohol, and 3 vols. 5 per cent, chromic acid), which gives better results than weak hydrochloric acid or any other method in common use. It is particularly valuable in examining Algae
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