leaving only the cornea and sclera to granulate and contract. These procedures have not taken, however, and never can take the place of enucleation. Each case presents its own features by which the surgeon must be governed; but perhaps it is only here that we may be justified in adopting the motto, attributed by the students to a celebrated professor of surgery, "when in doubt, operate."

ON THE ADOPTION OF THE METRIC SYSTEM IN

MEDICINE.

By E. DYER, A.M., M.D., HARVARD.,

OF PITTSBURG.

THE introduction of the Metric System into the United States has been much agitated during the past few years, and I beg the attention of the Society to a brief consideration of the subject.

The metric system was invented in France towards the close of the last century; and I shall spend a few minutes in explaining it in detail, before discussing its particular application to the prescribing of medicine.

The metre, which is the unit of length, and from which the units of measures, of weight, and capacity are directly derived, is oneten-millionth part of the distance from the equator to the pole, and is a little more than a yard in length. The measures smaller than the metre are derived from decimal divisions of it, and are designated by the Latin prefixes decem, centum, and mille. Thus, the tenth part of a metre is a decimetre, as our dime is the tenth part of a dollar; next is the centimetre or one-hundredth of a metre, as our cent is one-hundredth of a dollar; and the millimetre, onethousandth of a metre, is like our mill or tenth of a cent.

The multiples are designated by the Greek numerals, thus: The dekametre is ten metres, the hectometre is one hundred metres, and the kilometre one thousand metres, or about § of a mile.

The perfect simplicity of working long measure is evident. It saves every one who uses feet and inches the same time, trouble, and liability to mistakes, that the use of our decimal plan of coinage saves in the calculation of £., s., and d.

To get the measures of capacity a cube is taken, each side of which is a decimetre or one-tenth of a metre long. This is called a litre, and holds a little more than a quart. The subdivisions are made by the same prefixes as in the metre, i. e., one-tenth of a litre is a decilitre, one-hundredth of a litre is a centilitre, and one-thousandth of a litre is a millilitre. The multiples are dekalitre or ten

litres, hectolitre or one hundred litres-about twenty-five bushels-and the kilolitre or one thousand litres.

The unit of weight is derived directly from the unit of capacity. If a litre is filled with distilled water at its greatest density, 39° F., we shall have a body of water commensurate with a cubic decimeThe weight of a thousandth part of this, or a cubic centimetre, is called a gram.

tre.

The subdivisions of the gram are, the decigram or tenth part of a gram, the centigram or one hundredth part of a gram, and the milligram or one thousandth part of a gram. The multiples of the gram are, dekagram or ten grams, the hectogram or one hundred grams, and the kilogram or one thousand grams. Then comes the myriagram or ten thousand grams, etc. Such, gentlemen, is in brief the metric system, which, with the exception of the United States, Great Britain, and Russia, is used in every nation in Christendom: France, Germany, Spain, Italy, Portugal, Holland, Belgium, Mexico, Austria, Sweden, Brazil, Turkey, Roumania, Moldavia, British India, and all the South American States.

Its use was legalized by Great Britain in 1864, in the United States by Act of Congress in 1866, and made obligatory in the custom-house; and lately a commission has been confirmed by the Senate to attend the International Metric Congress, to be held at Paris this summer, 1878. In Russia it was legalized in 1870, and in 1877 it was adopted by the medical profession there.

A knowledge of it is required for admission into all the principal universities of this country, and it is taught in all the high schools of New England. We may safely predict that, to the second generation after us, the foot, the pound, and the quart will be merely matters of history.

Let us now consider the propriety of its adoption by the medical profession in this country. At any rate, let us make ourselves familiar with it, so that we may read intelligently the journals of foreign countries, and not look upon its use among us as an exhibition of pedantry and affectation.

The New York Medical Journal Association subscribes to seventytwo periodicals. In forty-one of these all contributions are made by physicians using the metric system, and in only thirty-one is our present system used. It is a fact that more than half of the valuable matter in our journals is borrowed from foreign ones, and, if we would read intelligently, we must be familiar with this system. It is recommended for its simplicity, convenience, and universality. It has been urged that it is complicated, that it is difficult to re

duce the present system of grains and ounces to it. Let us see. 15.434 grains are equal to 1 gram, therefore

Let us take an example. The following prescription is rendered in the metric system as follows:

Now looking at the two systems, and comparing them as to sim plicity, we find that in the metric we have a single unit of weight, the gram. In the old we have five, the grain, scruple, drachm, ounce and pound.

In the metric all substances are dispensed by weight. In the old, some by weight, others sometimes by weight, sometimes by measure. As to convenience: if, in taking the above prescription, we should wish to keep the dose the same but reduce the strength, for a child, to one-third the above, we see that of 2 grs. is of 1 gr., which no druggist could weigh. To get of oz. we must reduce it to 240 grs. and divide by 3, giving 80 grs.; and again reduce it to scruples, and write iv, or write out the whole number of grains, lxxx. All this is troublesome, and we shall find that many would resort either to starting a new prescription, or to patching up the original, half by guess and half by instinct, trusting to luck for

correctness.

In the metric system it is perfectly simple.of.12 is .04; of 15.00 is 5.00, and the menstruum remains the same. As to universality, there is no question but that it will soon become universal.

The Massachusetts Medical Society united in a petition to Congress in favor of its use, and many prominent practitioners of Boston have used it exclusively for more than two years. The New York Medical Society voted to adopt it as a body, and directed the secretary to notify all druggists to provide themselves with metric. weights, and it is fast supplanting the old system.

In a series of editorials, in favor of its adoption, in the New York Medical Record, 18 months ago, the following facts were stated, and if it served only as a new broom in obliging the druggists to provide themselves with new weights, much good would come of it.

It is stated that quantities of English-made graduates are sold and used in this country. And when it is considered that the ounce graduates are sold for $3 a dozen, any one can imagine how much time is spent in insuring their accuracy of graduation. When we also consider that there are 20 ounces to the pint in England to 16 here, we must expect gross inaccuracies which cannot occur in the metric system, where everything is dispensed by weight except when liquids are ordered in drops.

If this shows a bad state as to liquids, the weights are still worse. The editor of the Record found that a set of weights, of German make, were quoted on the price-list of a prominent firm in New York, as a complete set of 35 pieces for 34 cents. Also a set of grain weights, 4 pieces, for 10 cents. A set of the latter, being tested, gave the following results: gr..35, gr.=.90, 1 gr. 4 2.00. It will be seen that of these four, but one was correct, and that the others were respectively 10 per cent., 40 per cent., and 80 per cent. overweight.

1.10, 2 grs.

Another set, American make, consisted of 13 pieces, and sold for 25 cents. At an apothecary's, the first visited, the weights were found as follows: 3 grs. 2.75, 4 grs. = = 2.73, 5 grs. = 3.30, 6 grs.

=

grs.

=

=

=

3.15, 4 grs. 4.35, 6 grs.

=

= 4.43, 480 grs. = 458.85. At the second store it was found, 3 5.10. At the third, the weights were found correct, and at the fourth, permission of testing was refused. These examples are of course not conclusive, but they permit a fair inference that the whole country is flooded with cheap and inaccurate weights.

If we use the metric system, all the prominent druggists that we would allow to compound our prescriptions would supply themselves with new weights. And as they are new, and are stamped with the maker's name, and sold at a paying price, $5 giving 17 pieces and weighing 200 grams, we may expect that our patients will get what we order. Besides the danger of errors by the druggist is reduced to a minimum, as the Arabic figures are used and there can be no confusion of signs or numerals; while the weighing is as simple as making change in dollars and cents.

Another great advantage is, that by a little practice the physician can soon get to estimating the dose of drugs by per cent. For example, in the formula above we see that the amount of hydrarg.