THE CODEX AND THE BRITISH PHARMACOPOSIA. 
581 
made with a view to improve upon the ordinary minim measure, as you may 
see by several instruments which I have brought, for instance, Allsop’s graduated 
drop syringe, Gilbertson’s graduated tube with iiidia rubber-top, simple gra¬ 
duated tubes which may be used by plunging into the liquid, and placing the 
finger upon the opening of that end of the tube not in the liquid. But as far 
as my experience goes, I can measure as accurately and as quickly with an 
ordinary minim measure as can be required, and which can be more easily 
cleansed than any tube. The co7npte-gouttes might be useful to patients taking 
any particular medicine by drops ; but the system of drops, either in prescribing 
or administering medicines, should be eradicated from all well-regulated minds. 
Prescribers should at all times write minims when desirable, and not drops ; and 
for administration, all medicines should be at least diluted, so that nothing less 
than a teaspoonful should be given even to a child. 
I come now to the part relating to densities and areometers or hydrometers. 
It is often necessary—I quote the Codex—in pharmaceutic operations to bring a 
solution to a density determined upon, whether it be in the operations of 
crystallography or to obtain a constant or uniform state of concentration,—a 
knowledge of the density of a liquid being useful, within certain limits, to judge 
of the purity of the composition of some liquids. 
Baume’s areometer or hydrometer, which has been in use many years, is the 
one directed to be used. An account of it is given, but it is not necessary to 
reproduce it here, as it may be found in many works, especially Mohr and Red¬ 
wood’s ‘ Practical Pharmacy there are many density-tables in this part, and 
for reference undoubtedly frequently used,—the thermometers of Reaumur, 
Fahrenheit, and the Centigrade are those in general use, the Centigrade being 
exclusively adopted in this work ; there is a table of comparison, showing the 
relative Value of the three, then follow tables setting forth the fusing-point of 
different solid substances, the boiling-point of certain liquids, and the solubility 
in water of many substances used in pharmacy—winding up this part with a 
table of equivalents of elementary or simple bodies very similar to that of the 
P,B. There are two or three little discrepancies in the numbers, and the Codex 
enumerates amongst these substances, cadmium, cobalt, fluorine, nickel, silicon, 
and strontium, not contained in the P.B. table, omitting lithium, which is in it. 
This brings me to the Materia JMedica, which treats of those substances 
which are employed, either in the natural state or which take part in the for¬ 
mulae of the Codex. The first section or series comprises those substances which 
are obtained either from the vegetable or animal kingdom. Certain directions 
are given respecting the choice of these substances, to wit, the animals ; the 
parts or products thereof are very few, and are obtained in commerce. The best 
quality should always be selected of each kind. The so-called animals or their 
parts may at once be dismissed by simply naming them :—ambergris, lard, 
butter, bile or gall, spermaceti, cantharides, castor, wax, civet, cellar-woodlouse, 
cochineal, isinglass, hartshorn shavings, vine-snail, animal gelatine, frogs, cod- 
liver-oil, musk, oysters, cow’s milk, honey, eggs, and, lastly, the viper ; a strange 
collection, very useful and very good in their way. 
Vegetables, their parts or products, furnish, on the contrary, nearly all the 
materials of organic nature which are used in the preparation of medicines; 
those which are obtained in the ordinary way of commerce, should be carefully 
selected, and indigenous plants should be gathered, as regards age, season, and 
development, at the time when each part possesses in the highest degree the 
qualities which are sought for in them. Vide Codex. 
Before I make any remarks upon the different substances which constitute 
the vegetable portion of the Materia Medica, I may point out that in both books 
the arrangement is alphabetical. The Codex contains nearly double the number 
of substances that the R.B. does, and does not include among the vegetables 
