58 MOUNTING AND PREPARATION OF OBJECTS. 



Minute algse, infusoria, etc., require no previous 

 preparation, but may be at once placed in glycerine 

 and camphor water, by this means their original 

 colour is preserved and the growth of mycelium pre- 

 vented. It should be remembered that glycerine 

 cannot be employed as a preservative for objects 

 containing carbonate of lime, as it is a solvent of 

 that substance. Dr. Carpenter recommends its 

 saturation by pieces of marble as a preventative. 

 It is much safer to mount such specimens in dis- 

 tilled water to which a minute quantity of creosote 

 has been added. 



For further information as to the relative merits 

 of different media, we refer the reader to the works 

 of Klein, Carpenter, Beale, etc., mentioning at the 

 same time, that those recommended in these pages 

 will be found generally useful. 



Few more interesting objects present themselves 

 for examination than the Polycystina3, their variety 

 of form and beauty of outline, rendering them equally 

 a source of delight to the observer and of admiration 

 to the artist. 



Their distribution is very general, beautiful forms 

 being found in chalk, limestone, and many other 

 deposits. Large quantities are contained in the sand 

 removed from sponges, this may be obtained from 

 any chemist or sponge merchant without payment. 



The best method of separating them from the dirt 

 and debris, with which they are mixed, is to wash 

 the deposit in a large quantity of water with frequent 



