538 REPOirr — 1897. 



Experiments have been made to obviate the excessive transparency 

 which the more delicate parts (petals and the like) often assume when 

 preserved in spirit by precipitating salts in the tissues, but they have not 

 hitherto been attended with satisfactory results. 



For bulky objects, or for others in which flaccidity occasions no dis- 

 advantage, formalin maybe used in -5 per cent, to 15 percent, of the com- 

 mercial solution. It is cheaper than spirit, and in some cases preserves 

 the colour of the specimen in a more or less natural condition for many 

 months. This retaining of the colour, especially in the case of green 

 tints, is usually more effective if the specimen, rapidly killed by steam or 

 short submergence in strong alcohol, be treated for twenty-four hours or 

 longer Avith a strong bath of copper acetate. 



Further details of expex'iments with other liquids will be found in the 

 appendices of last year's report. Where the specimens are not intended to 

 be handled, drying in sand {vide appendix 1, Joe. cit.) gives admirable 

 results, and in many cases the natural colours are preserved. The extreme 

 fragility of the specimens thus treated constitutes, however, a serious 

 drawback when the objects are intended to be examined and handled by 

 students. 



No better methods of mounting specimens for exhibition purposes have 

 been devised than those in use in- the Museum of the Royal Botanical 

 Gardens in Edinburgh, an account of which is included in the interim 

 report already referred to. 



The Committee desire to express their thanks to those who have 

 kindly given them assistance by communicating such results of their own 

 observation and experience as were connected with the matters now under 

 consideration. 



