568 
PHARMACEUTICAL MEETING. 
such names we have in Hydrargyri Percldoridum and Hydrargyri Subchloridum. 
These names would correspond with those used for other similar compounds in 
the Pharmacopoeia, such as perchloride of iron and subacetate of lead. There 
ould never be any doubt as to which of the chlorides of mercury was meant by 
ither of these names, and they would sufficiently fulfil, in other respects, the 
requirements of a nomenclature for pharmaceutical or medical purposes. 
In the case of the nitrate of bismuth, which is at present called Bismuthum 
album , I would suggest that this name be changed to Bismutlii Subnitras . 
Next to the names applied to chemical compounds in the Pharmacopoeia, we 
have to consider the best means of representing the composition of such bodies. 
The mere name of a substance fails in most instances to give a precise represen¬ 
tation of its composition, and this is very frequently and conveniently supplied 
in chemical writings by the use of a symbolical formula in addition to the name. 
Such a formula defines a body much more precisely than usually can be done by 
any short and simple verbal description. But this method of chemical notation 
aims at a representation not merely of the composition, but also of the constitu¬ 
tion of bodies, and being altogether founded upon theoretical data, the practice 
of chemists in reference to it is subject to frequent changes as new views are 
adopted. This constitutes the objection, which appears to me a valid one, to the 
use of such formulae in a Pharmacopoeia. At the present time especially, it is 
well known that a great change is taking place in the system of notation adopted 
by chemists. The new method which is being introduced, although sanctioned 
by the highest authorities, is but partially adopted, and there are many impor¬ 
tant differences in formulae used by some even of our most eminent chemists. 
Are we to represent water by HO or by II 2 0 ? Is nitric acidNO s ,HO, or 
H, N 0 6 ', or H N 0 3 ? Is sulphuric acid S 0 3 , H O, or H, S 0 4 , or 1I 2 , S 0 4 ? Is 
oxalic acid C 2 0 3 ,3H0, or C 4 H 2 O s ,4HO, or C 2 II 2 0 4 ,2H 2 0? Is caustic pot¬ 
ash KO,HO, or KHO ? Should sal-ammoniac be represented by NH 3 ,IIC1, 
orbyNH 4 ,Cl? Should liquid ammonia be represented by NH 3 ,HO, or bv 
NH 4 0, or by NH 3 ,H 2 0, or by NILO ? 
Besides other objections and difficulties that stand in the way of maintaining 
a strictly scientific nomenclature, and selecting the best among the various me¬ 
thods of representing the composition of chemical compounds by symbolical for¬ 
mulae in the Pharmacopoeia, there is one that appears to me worthy of con¬ 
sideration, which is, that whatever method is adopted must necessarily be re¬ 
ceived and adopted by Pharmaceutical Chemists, and especially by pharmaceu¬ 
tical students, thus tending often to the exclusion of other approved methods, 
and tending to limit the course of chemical study. If. for instance, the compo¬ 
sition of water, nitric acid, caustic potash, calomel, corrosive sublimate and 
alcohol, be represented by H0;N0 5 H0;K0,H0;Hg 2 Cl; HgCl; and 
C 4 H s O+IIO ; with scientific names corresponding with these formulae; phar¬ 
maceutical students would find it necessary to learn a system of chemistry that 
accords with such a nomenclature and notation. They may thus to some extent 
be restricted from the study of chemistry as taught by eminent chemists, because 
this would clash with the theories involved in the chemistry of the Pharmaco¬ 
poeia, and a clashing of ideas in the meaning of names and symbols used in the 
practice of Pharmacy might be productive of much inconvenience and mischief. 
It appears to me desirable, with reference to nomenclature and notation, that 
the Pharmacopoeia should occupy neutral ground, as far as this can be done con¬ 
sistently with other objects which are required to be fulfilled. 
But if it should be determined to avoid the use of chemical names and sym¬ 
bols, such as are used by scientific chemists, what means are left to us for de¬ 
fining the composition of the substances of this class that are intended to be used 
in medicine ? We may give the composition of the substances as determined by 
analysis. It is upon the results of chemical analysis that symbolical formulas 
