On the specific gravity of different parts of the human brain / by H. Charlton Bastian.

  • Bastian, H. Charlton.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: On the specific gravity of different parts of the human brain / by H. Charlton Bastian. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    munication contains a record not only of differences fonnd to exist in the specific gravity of gray matter taken from frontal, parietal, and occipital convolutions respectively; but, also, I believe for the first time, of the specific weights of the optic thalami, pons, medulla oblongata, and different parts of the corpora striata, taken sepa- rately. Some of the facts so ascertained are very interesting, and seem to justify their early pubhcation. Owing, also, to the existence of certain discrepancies in the results arrived at by preceding inves- tigators and myself, it seems desirable that these discrepancies as well as our respective methods should be considered, with a view, if possible, of ensuring greater uniformity of results for the future. Investiga- tions of a delicate nature such as these, when conducted by different observers, are comparatively useless for the purposes of comparison, unless some uniform method be adopted. These considerations have induced me to make known the results of my own observations sooner than I should otherwise have done, and will, I hope, be deemed a sufficient justification for my bringing them forward before they are sufficiently numerous to enable me to draw any very safe deductions from them. The present paper may, therefore, be con- sidered as a first contribution towards the elucidation of a subject, at which I hope to work more thoroughly in the future. Dr. Bucknill, whilst physician to the ]3evon County Asylum, was the first to institute a series of observations upon the specific gravity of the brain, with a view of estimating the amount of 'relative' atrophy of this organ in the insane, in conjunction with another series of experiments for determining the amount of ' positive' atrophy of the organ in the same individuals. His first communi- cation on this subject, containing the results of the examination of thirty-two cases, is to be found in the 'Asylum Report' for 1852, and his next,* giving the details of the examination of another thirty cases, was published during the same year. He ascertanied the specific gravity by immersing portions of the encephalon in a solution of sulphate of magnesia, when by adding water or a strong solu- tion of the salt, until the cerebral mass hangs suspended in the fluid, without any tendency to float or sink ; and then by testing with the liydrometer, the specific gravity is thus found with great delicacy and facility, a difference of half a degree in the density of the fluid being indicated by the rise or fall of the substance im- mersed. In this second and more complete series of thirty cases—all chronic,, and including instaiices of dementia, imbecility, idiotcy, chronic mania, melancholia, epilepsy, and general paralysis—the average specific gravity of the cerebrum was found to be 1*0409, the extremes being 1-036 and r046 ; and of the cerebellum the average was I'O^S, the * • Lancet,' Dec. 25, 1852, p. 588.