CHAP. I. 
RAPHIDES. 
41 
separated by partitions, the intercellular passages of the 
bladders forming the partitions are sometimes left open, so 
that a free communication is maintained between all the tiers 
of air cells. 
4. Of Raphides. 
Among the tissue are found certain needle-shaped trans- 
parent bodies, lying either singly or in bundles, and called 
raphides. They were first discovered by Rafn, who found 
them in the milky juice of Euphorbim; afterwards they were 
met with by Jurine, in the leaves of Leucojum vernum, and 
elsewhere; and they are now well known to all vegetable 
anatomists. If a common Hyacinth is wounded, a consider- 
able discharge of fluid takes place, and in this myriads of 
slender raphides {Jig. 13.) are found floating; or if the cuticle 
of the leaf of Mirabilis Jalapa is lifted up, little whitish spots 
are observable, which are composed of them ; all these are 
acicular in form, whence their name. In Cactus peruvianus 
(Jig. 11.) they are found in the inside of the bladders of 
cellular tissue, and, instead of being needle-shaped, have the 
form of extremely minute conglomerated crystals, which, ac- 
cording to .Turpin, are rectangular prisms with tetraedral 
summits, some with a square, others with an oblong base. 
Crystals of a similar figure have been remarked by the same 
observer in Rheum palmatum (Jig> 12.) ; and their presence, 
according to him, is sufficient to distinguish samples really 
from China and Turkey, from those produced in Europe. 
The former abound in these crystals, the latter have hardly 
