2A1 
composed of phosphate or oxalate of lime, or some other 
compound of this earth, its value in the growth or nutrition 
of animals and vegetables, and that nature has established in 
certain plants a laboratory or storehouse of such calcareous 
salts, we get a glimpse of the utility of these crystals. They 
are plentiful in many parts which form the food of birds and 
mammalia, and medicine or food for man, and of which exact 
examples might be given in Thistle-seed and Duckweed, and 
numerous other plants. The well-known efficacy of Sarsa- 
parilla in certain cachexies is probably in great part due to 
the phosphate of lime composing the raphides so plentiful 
in this medicine, by which the quality of the officinal sam- 
ples of it may be tested, and its value as a remedy in the 
.Rickets of children suggested (‘Ann. Nat Hist.,’ June, 
1864, p. 510). In like manner the crystal prisms of Guaia- 
cum and Quillai and the raphides of Squill are noteworthy 
tests of the genuineness of those drugs, while we have 
already proved the use of raphides as diagnostics in sys- 
tematic botany. Nor will any one who may pursue the in- 
quiiy fail to admire and take pleasure in the objects. And 
when, by the periodic shedding of the leaves, the surplus 
crystals are restored, it is to fertilise the bounteous earth ; 
and withal, good reason appears why the gardener husbands 
decayed leaves for his composts, and why such plants as 
abound most in raphides, as do the 'Willow Herbs, Fuchsias, 
and Duckweeds, should be especially valuable in this 
respect. 
And now it is hoped that a sufficiently clear account has 
been given of Haphides, Sphseraphides, and Crystal Prisms, 
to enable even the merest novice easily and surely to find 
and discriminate these different plant-crystals, and at any 
season, either in town or country, while there can he no 
doubt that such observations -would afford an elegant and 
instructive addition to rural amusements. Thus, too, without 
application to dealers, the number of interesting and beautiful 
microscopic objects might be largely and very readily in- 
creased ; and the inquiry, if carefully and diligently' pursued 
to its legitimate conclusion, could hardly fail to extend the 
bounds of botanical science. 
