420 NATURAL SCIENCE. Dec, 1895. 



than in spirit, still it is but a question of time ere it vanishes. This 

 extraction is most marked and rapid in the highly-coloured sponges 

 and tunicates. Crustaceans, however, retain their colours well. 



In addition to the foregoing, I have further experiments with 

 formalin in progress, and trust to present the results at an early date. 



Taking every consideration into account, formalin may be 

 regarded, for the majority of purposes, as superior to spirit in the 

 results obtained, and when we remember its greater cheapness — a 

 gallon of strong solution costs on an average but is. — and the ease with 

 which we can apply it, it being miscible with water, spirit, and other 

 fluids in any proportion, we may account its introduction as one of 

 the greatest services ever rendered to the working biologist, while to 

 the naturalist in remote places, to whom restricted baggage is a 

 paramount consideration, formalin in its concentrated form will prove 

 an inestimable boon, bringing the formerly unattainable within easy 

 reach — all to the enrichment of our great museums and the advance- 

 ment of zoological knowledge. 



James Hornell. 



