290 
christison's dispensatory. 
tioris ; an exposition of thermometrical equivalents, with 
full tables exhibiting relations on the different scales, the 
effects of temperature, symbols, solubility of salts, and an 
explanation of terms used in prescriptions, from Gray's 
Supplement to the Pharmacopoeias. 
The Materia Medica proper commences in the usual 
way, the alphabetical arrangement being followed, which 
seems, time honoured, to be inseparable from a dispensa- 
tory. The information imparted under each head, is that 
found in the more recent treatises cm the Materia Medica. 
Where articles are derived from the vegetable kingdom, the 
plants affording them are referred to their appropriate 
natural history, position, under classes and orders, but few 
botanical details are indulged in. Medical botany is of 
secondary consideration, and the author is no doubt im- 
pelled to this by the full instruction which Scotch students 
receive in that department, and the co-existence of the ad- 
mirable treatise on the subject by Dr. Lindley. The account 
of drugs met with in the English market is clear and con- 
cise, and their chemical constitution correctly given, in 
accordance with the most recent analyses. 
There are certain subjects to which Dr. Christison ap- 
pears to have given especial attention ; the chapters upon 
these are peculiarly rich with information. Conium is one 
of them, which by him has been experimented on. The 
test for the activity of this drug, which originated with the 
Edinburgh College, is invaluable, we mean that by liquor 
potass83. Another of these is scammony. Dr. Christison's 
investigations into the purity of this drug, have presented 
the subject in its true light, and shown that the grossest im- 
positions have been practised. Sophisticated scammony is 
most common in the English market, and by the author has 
been divided into three kinds, which are termed calcareous, 
amylaceous, and calc-amylaceous. The worst of the 
specimens contained by analysis 42.4 per centum of resin. 
