pulverized window glass, both before and after heating, were passed through coarsely pulverized soda-lime and then over fresh phosphorus pentoxide. Not a trace of etherion remained. The same result was obtained when another lot of the siliceous sand already referred to was used as the source of etherion.

I will venture the conjecture that etherion will be found to consist of a mixture of three or more gases, forming one or more periodic groups of new elements, all very much lighter than hydrogen. If this proves true, I propose to retain the present name for the lightest one.

The transmission of radiant energy through space, has always been to me a fascinating phenomenon, and I have indulged in much speculation concerning the ether-that mysterious something, by means of which it is effected. The remarkable properties assigned to the ether from time to time in order to account for observed phenomena, have excited my keen interest; but I have long entertained the hope that some simpler explanation of the mechanism involved will be found. To me, a less strain of the imagination is required in the assumption that instead of a continuous medium, gaseous molecules of some kind, endowed perhaps with a mode or modes of motion at present unknown to us, are the agent of transmission; a gas so subtle, and existing everywhere in such small quantity, that it has escaped detection.

Perhaps the molecular hypothesis of the ether has proven so attractive to me, because it supports the hope that we may sometime compass the perfect vacuum,-a portion of space devoid of everything. Such a vacuum would be opaque to light, and gravitative attraction could not, I believe, act through it. It might afford a new point of view from which to study the profound mystery of gravitation; an outside point.

The late De Volson Wood' considered the question of a gaseous ether mathematically, and deduced certain necessary properties of the hypothetical gas, chief among which were exceedingly small density, and exceedingly high specific heat. Possibly we are about to find a gas which will fulfil the required conditions. It may be etherion, or its lightest constituent if it turns out to be a mixture. I venture to express the hope that etherion will at least account for some phenomena at present attributed to the ether.

1 Phil. Mag., Nov., 1895.

On account of the presumably extreme smallness of its molecules as compared with those of glass, etherion probably passes through the latter when any considerable difference of pressure exists on opposite sides, though the passage may be very slow. It seems to be condensed or compressed in glass as before indicated, and may evaporate on the side of lower pressure, and be absorbed on the side of higher pressure, after the manner of hydrogen in passing through palladium. In my own experiments, the heat transmission ascribed to the ether may be due to the presence of the new gas inside the bulb. A small fraction of a millionth would be sufficient, and this might escape detection by the pressure-gauge, on account of the necessary compression in the gauge head causing absorption by the glass. Again, etherion must always be present to some extent in all "vacuum tubes" (as well as in my own conduction bulb) on account of its long-continued evolution from glass; and may be the medium of propagation of the Roentgen rays in the vacuum glass and air.

ON THE FACILITIES FOR STANDARDIZING CHEMICAL APPARATUS AFFORDED BY FOREIGN GOVERNMENTS AND OUR OWN.'

IT

BY LOUIS A. FISCHER.

Received October 17, 1898.

is at the invitation of your esteemed president, Dr. C. E.

Munroe, that the Office of Standard Weights and Measures submits for your consideration and information this paper, stating what facilities are afforded by foreign governments and our own for the standardization of chemical apparatus. It is but proper that such information should be furnished by this Office ; for it, more than any other bureau of the government, is called upon to make the determinations referred to. But before going further, a brief history of the Office will be given, in order that its position and condition may be understood.

The origin of the Office may be said to date from May 29th, 1830, when the Senate passed a resolution calling upon the Secretary of the Treasury to cause to have made a comparison of the weights and measures in use at the principal custom-houses.

1 Prepared and read before the American Chemical Society, Boston, August, 1898, by direction of Dr. Henry S. Pritchett, Superintendent U. S. Coast and Geodetic Survey, and Standard Weights and Measures.

This task was entrusted to Ferdinand R. Hassler, the then superintendent of the Coast Survey, who discovered large discrepancies among the standards in use. His report led to the establishment of a shop and laboratory, in which copies of those standards adopted by the Department were made and compared. The task was entered upon by Mr. Hassler with his usual foresight and energy; and early in 1836 we find the statement in one of his reports that "forty weights, two pint measures, and four sets of yard standards are ready for final adjustment."

When we consider that the zinc used in the construction of these standards was mined and purified by Mr. Hassler; that machinery and apparatus had to be designed and built; and that the proper working force had to be organized, we cannot help admiring the tremendous energy of the man. So satisfactory were the operations that in June, 1836, Congress passed the following resolution :

"Resolved, That the Secretary of the Treasury be, and he hereby is, directed to cause a complete set of all the weights and measures adopted as standards, and now either made or in the progress of manufacture for the use of the several custom-houses, and for other purposes, to be delivered to the Governor of each state in the Union, or such person as he may appoint, for the use of the States, respectively, to the end that a uniform standard of weights and measures may be established throughout the Union."

For the first ten years the entire efforts of the office were devoted to the construction and verification of standards of length, weight, and capacity. These operations required the construction and investigation of comparators, balances, thermometers and barometers; and the determination of the expansion of water and metals, and the solution of other physical problems.

About 1842 the questions of hydrometers and sugars were referred to the Office, then under the direction of Prof. A. D. Bache. The exhaustive report,' made in 1848 by Prof. R. S. McCulloh, who had charge of the investigation, has become standard; and the alcoholometric tables now used by the Treas

1 Reports from the Secretary of the Treasury of Scientific Investigations in relation to Sugar and Hydrometers, by Professors Bache and McCulloh, 1846; Executive Document No. 50; 30th Congress, Ist session.

ury Department in the collection of duty on spirits differ but slightly from those submitted in the report.

The passage of the law of 1866, legalizing the Metric System, and directing that each state in the Union be supplied with copies of the metric standards, again imposed duties upon the Office which occupied its attention for many years.

In 1891, and again in 1897, the Office was represented on scientific commissions appointed for the purpose of discovering and reporting upon the cause of discrepancies in sugar determinations, by means of the polariscope, at the various ports of entry. As was suspected at the time, much of the trouble was traced to the use of erroneous standards, especially of capacity. Errors were also caused by the use of erroneous values assigned to the quartz control plates by their manufacturers; and, also, by ignoring the effect of temperature on the rotation of the sugar solutions and plates.

As a result of the report of the first commission, the Office was called upon to standardize control plates, and to devise means for rapidly verifying the large number of tubes, weights, and flasks used in sugar laboratories. No apparatus is now used by the Customs Service unless it has first been examined by the Office of Weights and Measures. Nothing illustrates the necessity of having verified apparatus more than the case just cited. In many instances flasks supposed to contain 100 Mohr cc. were found in error as much as one-half cc., and it soon became manifest that if the flasks were to be used without appreciable error they would have to be graduated by the Office. Accordingly, the arrangement here shown' was devised for graduating the flasks; and between 2,000 and 3,000 have been graduated during the past six years.

The flasks, samples of which are afterwards tested, must not show a greater error than 0.05 cc.; and no difficulty has been encountered in keeping within this limit. The Office is, therefore, prepared not only to standardize flasks, but also to mark them, provided the interior diameters of the necks do not exceed fifteen mm. or fall below ten mm. There is no reason, however, why this kind of work should be done for the general public, for the same accuracy may also be attained by 1 For description of device see pages 924 et seq.

manufacturers. No special skill is required to manipulate the device used by us, and a speed of twenty flasks per hour may be maintained without extraordinary effort.

The Office of Standard Weights and Measures is not required by law to make comparisons for other than official purposes; but inasmuch as we have in our care the national standards, it has been the policy of the Office for years past to endeavor to meet all demands. Our means, however, are very limited, compared with those provided by other governments for bureaus doing similar work. Germany has its 'Physikalisch-Technische Reichsanstalt', where both scientific and technical research are carried on. This institution has two sections, the duties of which are as follows:

SECTION I.

1. The performance of physical investigations and measurements which tend, preeminently, to the solution of physical problems of great scope and importance in a theoretical or practical direction, and which demand a greater outlay of instrumental equipment, consumption of material, or time of observers and computers, than can, as a rule, be offered by private individuals or educational institutions.

2. The solution of matters referred to it by Section II, in so far as the equipment of the latter is insufficient for their accomplishment.

SECTION II.

1. The execution of such physical or physico-technical investigations as are directed by official authorities or designed to promote precise machine construction, or other branches of German industry.

2. Verification of measuring apparatus and instruments of control, so far as they do not lie in the domain of weights and measures; the determination of the errors of graduation of such instruments, and the issuance of certificates of results.

3. Construction of instruments and parts of instruments, as well as the execution of other mechanical work for German state institutions and authorities, in so far as their construction by private workshops gives rise to difficulties.

4. In special cases the construction of parts of instruments for