86 
BRITISH FERNS. 
donne un joli gris ;” so we find that from this group we 
get three good dyes, “ durable blue,” “ pretty grey,” 
and pleasing yellow.” 
Even the Equisetum arvense has medical and edible 
qualities, according to M. Duchesne. Dried, it is used 
as an astringent and diuretic in Vienna, he says, and in 
Italy the young shoots are used for food. 
The virtues of Dutch rushes need little setting forth. 
The crystal -laden stems are useful for polishing wood 
and metals, for cleaning, and everything that can be 
furbished and brightened by a good scrubbing. The 
very round stems are used (according to M. Duchesne) 
for enlarging the holes in flutes, and for polishing the 
holes in clocks and watches. Gilders use them to 
^adoucir le blanc qui sert de couche a Tor.” Perfu- 
mers use them to reduce the talc to powder and make it 
a fit basis for the essences. 
We thus find that the observation and ingenuity al- 
ready applied to the ferns and their allies, has discovered 
a few important uses and a great number of lesser ones. 
Further study and observation will doubtless discover 
more, and we may well expect such a result in days 
when fern- collectors are so numerous and so perse- 
vering. 
