« AnteriorContinuar »
Dr. Hayes called the attention of the Fellows to the fact, that
“ The urinary deposition called red sand, which presents such welldefined crystals, is a compound body, having generally a large quantity of oxalate of lime crystallized with it. Crystals of various forms and colors were shown under the microscope. Lithic acid, ammonia, coloring matter, and oxalate of lime are the most common and obvious ingredients assuming a crystalline form. Oxalate of lime, as inferred from more than twenty-five analyses of different urine samples, is always present, and may be detected both by spreading a layer of aqua ammonia on the surface of recent urine, when the salt crystallizes, and by adding hydrochlorate of lime to recent urine, washing the precipitate and subsequent analysis. Recent healthy urine is always acid; but this state is not produced by carbonic acid, united to the phosphates, as has been supposed. When salts of lead, lime, baryta, or magnesia are added, the acidity is preserved unchanged. The carbonic acid usually present is disengaged by a powerful acid, with the effervescence due to its gaseous form, but, independently of this, there exists an acid reaction. It has been assumed that oxalic acid is absent in cases where no crystals of oxalate of lime separated from samples of urine preserved. If the acid action is very marked, such cases are no exceptions, for in urine we do not expect unfailing chemical decompositions of salts. Besides, it can be shown that, even in alkaline urines, oxalate of lime separates as red sand, and covers the surface after several days of exposure for deposition. These, with other observations, lead to the conclusion, that we are far from possessing a true knowledge of the composition of this important secretion. A true analysis can only be made by operating on recent urine, by precipitations and evaporations, without loss of time and aid of heat ; the more important constituents are otherwise converted into secondary products of the steps of the analysis.”
Professor Horsford read a paper from Mr. Breed of the Lawrence Scientific School, giving an account of a series of experiments on the nature of vesication, and showing that the process was totally independent of evaporation.
Professor Horsford also exhibited a Daguerreotype of the moon, taken in front of the eye-glass of a telescope, by Mr. Wells of the Scientific School.
Three hundred and twenty-seventh meeting.
February 6, 1850. — MONTHLY MEETING. The PRESIDENT in the chair.
Professor Gray, from the Publishing Committee, announced the publication of a new half-volume of the Memoirs of the Academy, namely, Vol. IV. Part I. (new series), and laid a copy on the table.
Professor Peirce made a communication on a new method of computing the constants of the perturbative function of planetary motion.
“ The researches of Laplace and Legendre left the theory of these constants, and of their mutual relations, in a state which seems to require no farther development. But their methods of computation consisted in formulæ, by which the constants were derived from each other in such a way, that the defects of imperfect approximation were aggravated at each step, and finally became intolerable in the more remote constants and their higher differential coefficients. The labors of Pontecoulant varied in some degree the form, but not the nature or extent, of these difficulties. In his theory of Mercury, Leverrier has discussed the defects of the old form of computation, and proposed a new method, by which each constant and differential coefficient is determined directly, either from the usual series in the case of the constant itself, or from a very ingenious transformation of the series in the case of the differential coefficients. Leverrier has proposed and executed the exact determination, once for all, of the coefficients of these series, but has not yet published them. I was also permitted, several months ago, to examine a table of Leverrier's coefficients, which was calculated with the greatest care by Mr. Sears C. Walker. Leverrier's transformations were derived from observing that the successive terms of the original series differ very little in the values of their coefficients. A recent examination of the forms of these coefficients has led me to make the computation of the constants and of their differential coefficients depend upon certain auxiliary series, which approximate as much more readily than Leverrier's as his transformed series do in comparison with the original series. The principle of this new approximation consists in the very small difference which may be observed between the corresponding terms of different series, instead of between those of the same series. In the new method, the different constants are not computed independently of each other, but by such successive steps, that any error or defect of approximation continually diminishes in its effect, and gradually dies out. This want of independence of computation may sometimes be regretted, but since the whole series of constants is usually needed at the same time, it will oftener be a gain, for it will give the means of verifying the whole series by a few independent computations corrected by Leverrier's tables. The two methods are not, therefore, to be regarded as antagonistic, but rather as complementary.
“I have the honor of laying upon the table my formulæ, and a table of the coefficients of my fundamental auxiliary series, computed with great care by Mr. J. D. Runkle, who is an assistant in the preparation of the Nautical Almanac."
Mr. Teschemacher read a paper on two minerals, Struvite and Gahnite, giving an historical account of them, and showing their identity. He also exhibited specimens of native bicarbonate of ammonia, taken from a deposit, said to be of great extent, found on the shore of Terra del Fuego.
Professor Guyot gave a verbal account of the method formerly pursued, and the instruments employed, in the meteorological observations made throughout the State of New York; also of the system now adopted by the Regents of the University of that State, to be carried on uniformly at a great number of stations, established under his supervision, in conformity with the plan recommended by the Secretary of the Smithsonian Institution. He hoped that this system would be adopted in all the States, and thus uniformity, and a ready mode of comparing the results, be secured. He concluded by offering a preamble and resolutions, with a view of obtaining the coöperation and aid of the Legislature of Massachusetts in establishing such meteorological observations in Massachusetts, in connection with the contemplated sanitary survey of the State ; and moved that a committee be appointed to take the subject into consideration. Messrs. Guyot, Peirce, Lovering, Treadwell, and Bowen were appointed the committee.
Mr. Guyot also described the apparatus employed at the Observatory at Toronto, by which the variation and the minute oscillations of the magnetic needle are self-registered photographically; and exhibited several specimens of such records.
Mr. Paine briefly recapitulated some of the results of the thermometrical observations he had carried on, in Boston and its vicinity, during the last twenty-six years.
He also moved the appointment of a new committee on the Rumford Observations, of which the late Dr. Hale was formerly chairman, but from which there had been no report since his death.
Messrs. Treadwell, Peirce, and Charles Jackson, Jr., were constituted the committee.
Dr. A. A. Hayes presented for examination, specimens of Stereoptene, or the camphor derived from crude oil of valerian, in the forms of solid, clear crystals and elongated porous prisms.
“ This oil, which is manufactured by the society of Shakers, at Enfield, New Hampshire, from the roots of the English valerian, contains, with the volatile oil of the root, all the valerianic acid. It is well known that the oil as usually obtained contains valerole, valerianic acid, and borneole. By repose for several months, imperfectly guarded from the atmosphere, a crystalline aggregate withdraws from the compound oil, in an impure state. These crystals are readily purified by the usual processes. In the most regular form, they were measured by J. E. Teschemacher, Esq., who refers them to the rhombic system, — form, a right rhombic prism, with angles M on M' 12120, and 5842, while M on e, the terminal plane, is 13430.' Its general form is that of thin elongated prisms; cooled from a fluid, it gives a crystalline mass ; sublimed, it forms snow-like flakes, or stellæ. The crystals have a high lustre, and a clear white color, with a slight, but peculiar odor. Masses suddenly cooled have the specific gravity 1.030, and crystalline fragments float indifferently in sulphuric acid, specific gravity 1.076, at 60° F. This substance melts at 198° F., remains fluid at 195° F.; its fusing-point, as determined, is between 196.7o and 197.2° F.
“Mr. Adolph Schlieper performed the analysis, after attempts with oxide of copper, by means of chromate of lead, as the oxidizing body. The crystals by fusion lose the elements of water, but when dried in warm air over sulphuric acid,
1. 0.304 grm. gave 0.851 grm. carbonic acid, and 0.305 grm, water.
2. 0.2513 grm. substance gave 0.705 grm. carbonic acid, and 0.2503 grm. water.
3. 0.290 grm. substance gave 0.811 grm. carbonic acid, and 0.293 grm. water.
“Calculated for 100 parts, we have for the empirical formula, C 8, H 7, O, or, Calculated,
76.34 76.51 76.26
0 = 8= 12.70 12.52 12.44 12.52 “All attempts on the part of Mr. Schlieper and myself to form compounds with chlorine, hydrochlorine, or other acids, failed; but the deductions of Mr. Schlieper which follow show clearly that this new body belongs to the large class of Stereoptenes, or camphors of the volatile oils.
“ As a valerian camphor, its probable formula is obtained by multiplying the empirical formula by the number 5, or,
C 40, H 35, O 5, = Valerian Camphor. “ Under this view, it appears to be derived from borneole, C 10, H 8, by the process of oxidation, in presence of water and atmospheric air ; thus, 4 equiv. borneole + 3 equiv. water + 2 equiv. oxygen, form the crystallized body. 4 (C 10, H 8)=C 40, H 32
3 H, 0= H 3,0 3
C 40, H 35, 0 5=Valerian Camphor." Mr. Dana communicated, through the Corresponding Secretary, a continuation of his account of the Crustacea collected in the cruise of the United States Exploring Expedition, viz. :