Fah., accompanying ordinary febrile disturbances. The peculiarity attending the rise of temperature in disease is that it is not much felt by the patient himself. In mild intermittent fever and in tubercular consumption, the heat of the body will often be found 14° or 2° above the standard of health, while no sense of unusual heat, and sometimes no bodily discomfort of any kind, is felt by the sick man. Even in the more serious fevers, where the temperature goes up to 102°, 104°, or higher, there is not always a sense of increased heat proportioned to the disturbance of temperature: and moreover, the state of the temperature is governed mainly by the severity of the disease, and not by such external circumstances as the heat of the weather and the amount of clothing.

The great and long continued heat of the summer of 1870 gave me an opportunity, which seems unlikely to recur during the present summer, of investigating on myself to what extent the temperature of the healthy body was liable to rise under the influence of oppressively warm weather.

In the course of my experiments the highest temperature that I found was that of 997 Fah. At this temperature I felt quite unpleasantly overheated, but not as much so as I would have been if instead of spending the morning indoors, I had been exposed to the rays of the sun in the open air. When the temperature of my body was below 99° I never felt uncomfortably hot. In fact, I satisfied myself by repeated trials, that a temperature of 99°-2 must be reached before the sensation of I suffering from heat comes on.

During the hottest weather, I was able, by the prolonged use of the shower bath, to reduce my temperature to 97°.7. If, while at or about this temperature, I went into the street in the middle of a very hot day, the greatness of the heat was plainly felt as a sensation, but not as a cause of discomfort, as a man in cool weather might feel the glow of a furnace near which he was standing without being distressed by it. In fact, until my temperature had risen to 99°, I merely perceived how hot it was without being troubled by it.

It would thus appear that the discomfort we feel in hot weather is not from the impression of heat on the surface, but from the secondary effect of the heating up of the whole body; or rather, it is only when the heat of the whole body has risen nearly 1° Fah. that a check of the surface cooling begins to be unpleasant.

Very great elevations of temperature have been observed in sun stroke or heat apoplexy. That in all such cases the heat of the body rises above 100° Fah. before alarming symptoms manifest themselves, I think highly probable. Accurate thermometric examinations of mild cases of sun stroke and of perAM. JOUR. SCI-THIRD SERIES, VOL. II, No. 11.-Nov., 1871.

sons supposed to be on the verge of apoplexy from excessive heat, may be pointed out as scientific desiderata.

In the Philos. Trans. for 1792 are to be found some curious experiments by Dr. James Currie, on the cooling of the human body by cold baths. He carried the reduction of temperature as low as 88° Fah., and this seemed, from the symptoms pro-t duced, to be as far as the heat of the body could be reduced with safety. It is to be hoped that some one may supplement these researches by experiments in the direction of the elevation of the animal temperature.

ART. XLII.-Preliminary Catalogue of the bright lines in the Spectrum of the Chromosphere; by Č. A. YOUNG, Ph.D., Professor of Astronomy in Dartmouth College.

The following list contains the bright lines which have been observed by the writer in the spectrum of the chromosphere within the past four weeks. It includes, however, only those which have been seen twice at least; a number observed on one occasion (Sept. 7th) still await verification.

The

The spectroscope employed is the same described in the Journal of the Franklin Institute for November, 1870; but certain important modifications have since been effected in the instru ment. The telescope and collimator have each a focal length of nearly 10 inches, and an aperture of of an inch. prism-train consists of five prisms (with refracting angles of 55°) and two half-prisms. The light is sent twice through the whole series by means of a prism of total reflection at the end of the train, so that the dispersive power is that of twelve prisms. The instrument distinctly divides the strong iron line at 1961 of Kirchhoff's scale, and separates B (not b) into its three components. Of course it easily shows everything that appears on the spectrum maps of Kirchhoff and Angstrom. The adjustment for "the position of minimum deviation" is automatic; i. e., the different portions of the spectrum are brought to the center of the field of view by a movement which at the same time also adjusts the prisms.

The telescope to which the spectroscope is attached is the new Equatoreal recently mounted in the observatory of the College by Alvan Clark & Sons.

It is a very perfect specimen of the admirable optical workmanship of this celebrated firm, and has an aperture of 9 inches, with a focal length of 12 feet.

In the table the first column contains simply the reference num ber. An asterisk denotes that the line affected by it has no wel marked corresponding dark line in the ordinary solar spectrum

The second column gives the position of the line upon the scale of Kirchhoff's map-determined by direct compariso with the map at the time of observation. In some cases an interrogation mark is appended, which signifies not that the erist ence of the line is doubtful, but only that its precise place could not be determined, either because it fell in a shading of fine lines, or because it could not be decided in the case of some close double lines which of the two components was the bright one; or finally because there were no well marked dark lines near enough to furnish the basis of reference for a perfectly accurate determination.

The third column gives the position of the line upon Angstrom's normal atlas of the solar spectrum. In this column a occasional interrogation mark denotes that there is some doubt as to the precise point of Angstrom's scale corresponding to Kirchhoff's. There is considerable difference between the two maps, owing to the omission of many faint lines by Angstrom, and the want of the fine gradations of shading observed by Kirchhoff, which renders the coördination of the two scales sometimes difficult, and makes the atlas of Kirchhoff far supe rior to the other for use in the observatory.

The numbers in the fourth column are intended to denote the percentage of frequency with which the corresponding lines are visible in my instrument. They are to be regarded as only roughly approximative; it would of course require a much longer period of observation to furnish results of this kind worthy of much confidence.

In the fifth column the numbers denote the relative brilliance of the lines on a scale where 100 is the brightest and 1 the faintest. These numbers also, like those in the preceding column, are entitled to very little weight.

The sixth column contains the symbols of the chemical substances to which, according to the maps above referred to, the lines owe their origin.

There are no disagreements between the two authorities; in a majority of cases, however, Angstrom alone indicates the ele ment, and there are several instances where the lines of more than one substance coincide with each other and with a line of the solar spectrum so closely as to make it impossible to decide between them.

In the seventh and last column the letters J., L. and R. de note that to my knowledge the line indicated has been ob served and its place published by Janssen, Lockyer or Rayet It is altogether probable that a large portion of the other line contained in the catalogue have before this been seen and lo cated by one or the other of these keen and active observers but if so I have as yet seen no account of such determing tions.

I would call especial attention to the lines numbered 1 and 82 in the catalogue: they are very persistently present, though faint, and can be distinctly seen in the spectroscope to belong to the chromosphere as such, not being due, like most of the other lines, to the exceptional elevation of matter to heights where it does not properly belong. It would seem very probable that both these lines are due to the same substance which causes the D3 line.

I do not know that the presence of Titanium vapor in the prominences and chromosphere has before been ascertained. It comes out very clearly from the catalogue, as no less than 20 of the whole 103 lines are due to this metal.

Hanover, N. H., Sept. 13, 1871.

ART. XLIII.—The precise Geographical position of the large masses of meteoric iron in North Mexico, with the description of a new mass-The San-Gregorio Meteorite; by J. LAWRENCE SMITH, Louisville, Ky.

ISOME of the remarkable masses of meteoric iron in Northern Mexico have been known to travelers for a number of years; but no very precise information concerning them had been given until the year 1854, when the first mass, brought from that locality, was placed at my disposal by Lieut. Gouch of the U. S. Army, and was described in a memoir on meteorites published in the American Journal of Science, April, 1854; it is now in the Smithsonian Museum, and weighs 252 lbs.

On the return of Mr. Bartlett, of the Boundary Commission, I learned of two other masses in that region, and Lieut. John G. Parke, of the U. S. Army, placed a fragment of one of them in my possession; the fragment of the other mass was lost. I figured and described both of those meteorites in the memoir just alluded to; the first, which I called the Tucson Meteorite, is now in the Smithsonian Institute, and weighs, I believe, several thousand pounds; the second one I called the Chihuahua iron, and is still at the Hacienda de Conception, where it was first found. Still later in the year 1868, Dr. H. B. Butcher placed under my examination eight masses of meteoric iron that had been brought to the United States from the same region of Mexico; these I examined, and published a full account of in the American Journal of Science. These masses are now in Philadelphia, still owned by Dr. Butcher, and vary in weight from about 300 lbs. to 800 lbs. Dr. Butcher having returned to Mexico, I requested him to get all possible information in regard to the geographical position of these bodies; this he