LEEDS CHEMISTS’ ASSOCIATION. 
4G«J 
the meantime the term “ vital principle,” as indicating an internal force, must be given 
up as completely as is the use of the word “ caloric ” in relation to heat. The deeper 
our investigations into this most important subject, the more confirmed would be our 
reverent sense of how much there was relating to man that must ever be a mystery to 
our finite senses. 
The cordial thanks of the Association were voted to Dr. Allbutt on the motion of Mr. 
Harvey, seconded by Mr. Thompson. 
The Fifth Meeting of the session was held February 8, 18G5 ; the President in the 
chair. 
Mr. E. Thompson read a paper “ On the Pharmacopoeia of the United States.” He 
commenced by pointing out that a similarity in race, language, and literature between 
the people of the United States and ourselves, gave an interest to all books issued by 
them which did not apply to those published in other countries, as, for instance, those of 
the continent of Europe. In medicine, as an inexact science, national peculiarities 
exercise much influence of a kind not felt in relation to exact sciences like astronomy. 
'Thus the use of particular remedies is often confined to particular countries. The 
system of therapeutics of the United States may be broadly considered to be identical 
with our own, possibly our American brethren being too ready to adopt new remedies, 
whilst we are apt to adhere to those which modern research has shown to be useless. 
The authority attaching to the United States Pharmacopoeia is quite different to that 
recognized in our own. There is no law to command its exclusive use. It takes its 
origin in a voluntary association of physicians and chemists, consisting of delegates from 
the incorporated colleges, etc., of medicine and pharmacy throughout the country. Thus 
the druggist meets the physician upon equal terms in settling the standard by which 
one party is to prescribe, and the other to dispense. The work is revised every ten 
years; the issue of the present, which is the fourth, having been in 18Go. 
The arrangement of the work is very similar to that of our own. Tables are given of 
the alterations made upon the last edition. The ordinary list of the Materia Medica is 
followed by what is called a “Secondary List” of such drugs as have not attained 
sufficient standing to be admitted to the “ Primary List,” or of drugs falling into disuse. 
Troy weight is adopted, but the use of the term “ pound” is avoided. The ounce is 
also called “ troy ounce.” The drachm and scruple are not used, but their value given 
in grains. For measure, the pint of sixteen ounces is employed, the ounce being subdi¬ 
vided into drachms and minims. We may see in these arrangements more wisdom than 
has characterized the action of British legislation, since old names are not appropriated 
for new weights and measures, as in the case of our pound, pint, and ounce. However, 
it appears strange that in a country with a decimal system of coinage, the above anti¬ 
quated system of weights and measures should have lasted so long. 
Much difference of opinion has existed in our own country as to the process best 
adapted for the preparation of tinctures. It might have saved trouble had the condi¬ 
tions been first determined which favoured either percolation or maceration. To 
order percolation, without defining the shape of the percolator, the fineness of the 
powder used, or the pressure in packing, was leaving too much to the discretion of the 
operator, and was calculated to bring the process into discredit. The instruction of the 
British Pharmacopoeia would indicate a compromise between the advocates of the two 
plans. The United States Pharmacopoeia adopts percolation wherever applicable, but 
gives specific directions for each case. In the first place, five degrees of fineness of 
powder are defined. A powder passed through a sieve of 80 or more meshes to the 
linear inch, is designated as very fine; through one of GO meshes, fine ; through one of 
f>0 meshes, moderately fine; through one of 40 meshes, as moderately coarse; and 
through one of 20 meshes, as coarse. In the preparation of tinctures, the degree of fine¬ 
ness of the powder is always indicated. The shape of the percolator, whether cylindrical 
or conical, is also indicated, and the degree of pressure to be used in packing the ingre¬ 
dients. 
The United States Pharmacopoeia admits a class of preparations called Fluid Ex¬ 
tracts. They may be described as tinctures concentrated by evaporation or distillation, 
sometimes with sugar added. A waste of alcohol would be an objection to some of 
them, but they appear to deserve notice. There are more than twenty such prepara¬ 
tions. 
