THE TAMWORTH TREASURE TRO\'E. 159 



On the obverse PILLEMV EEX, and on the reverse BEVNING 

 ON TANPI. 



Bruning was a coiner, or moneyer, of Tamworth in the time of 

 Edward the Confessor, and continued in the reign of William 11. 



Pitt mentions another silver penny of WiUiam 11. having on the 

 reverse lELFPINE ON TAM. 



KAPHIDES AND PLANT CKYSTALS. 



BY MRS. G. R. CO'U^N. 



Deposits of mineral matter in a crj'StaUine form are frequently 

 found in vegetable cells, where they are at once brought into view by the 

 use of polarised light. They are commonly termed Eaphides, or needle- 

 shaped bodies, a term inappropi'iate to many of them, in. which the 

 crystals are of different forms, often piismatic or stellate. 



As early as Malpighi's time, Eaphides had been observed in plants, 

 and at later periods they engaged the attention of Quekett, Lindley, 

 Bchleiden, and others, but they appear to have looked upon them as 

 products of disease, or an accidental cii'cumstance in the economy of the 

 plant. The first to reduce to something like order, and to indicate the 

 value of plant crystals, both as a constant and intrinsic result of the 

 healthy life of cei-tain plants, and also in determining the differences 

 between species, was Professor George Gulhver, by whom they have 

 been arranged in three groups, viz. : Ea^Dhides, Sphseraphides, and 

 Crystal prisms. 



The crystals are mostly composed of oxalate of lime, sometimes with 

 magnesia. In other instances the calcareous base is combined with 

 tartaric, citric, or maUc acid, and the acicular crystals usually consist of 

 phosphate of lime. 



Eaphides are slender, needle-shaped crystals, with rounded smooth 

 shafts vanishing at each end to a point. About ten to fifty or more lie 

 parallel together, so as to form a bundle which partially fills a cell, or 

 intercellular space. When undisturbed, this bundle hes along its cell, 

 but the Eaphides are so easily displaced by slight pressure that either all 

 or pai-t of them cross the cell in various directions, sometimes escaping 

 from the ends. The raphis-cell is commonly very distinct, often oval, 

 and contains some viscid,, semi-fluid substance, in the midst of which 

 lies the bundle of Eaphides. The raphis-bearing plants among our 

 native exogens belong to three orders, Galiacese, Balsaminaceae, and 

 Onagracete, and there is not a single instance of any species belonging to 

 these orders without Eaphides. 



The Fuchsia belongs to the order Onagracese, and is a great raphis- 

 bearing plant, quantities being found in the leaves, the beiiy-pulp, 



* Abstract of a paper read by Mrs. Cowen before the Natural Science Section of 

 the Nottingham Literary and Philosophical Society, on April 3rd, 1878. 



