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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    extremes ranging between 1039 and ]*046. In tlie first series, containing a few acute cases, the specific gravity of the cerebrum varied between 1-036 and 1-052, the mean being 1-041; whilst that of the cerebellum varied between 1-037 and 1-053, its mean being 1-043. Unfortunately, however, these results, as far as the cerebrum is concerned, are rendered comparatively valueless, owing to the method adopted. Dr. Bucknill says:—In many instances I took the specific gravity of the whole organ, but finding it was invariably lower than any of its parts, and that it was impossible to free so large a mass from air bubbles, I discarded the results as untrustworthyand further on he states that the figures in his tables refer to large pieces of brain containing a fair proportion of vesicular and tubular substance. This is, indeed, as unsatisfac- tory a process as the other, since subsequent observations have shown the differences existing between the specific gravities of the gray and white matter of the cerebrum ; for, how is it possible to ensure pre- cisely the same relative proportions between these two substances in all the portions of brain taken for examination ? And even were it possible to do this, the result would still be a crude one, capable only of being compared with others of the same kind, and revealing nothing with regard to the separate specific gravities of gray and white matter respectively—each of which, as is now known, may vary independently of the other, and so exert more than a fair share of influence upon the number obtained. A high specific gravity of gray matter might even be masked by a slight softening of the white substance—a combination occasionally met with amongst the insane, and which, when it occurs, would, by this method, yield a mean number in every way deceptive. About the same time that Dr. Bucknill published his second table. Dr. Aitken's attention was attracted to the subject of the specific gravity of the brain by some abservations which he made on the central ganglia in a case of chorea.* He found the combined corpus striatum and optic thalamus on the right side to have a specific gravity of 1-025, and on the left 1-031. This induced him to make other observations upon the brains of persons dying in the Eoyal Infirmary of Glasgow, in order to compare the specific weights of the central gangha on the two sides of the body with one ano- ther, and with that of the cerebrum and the cerebellum. The results of the examination of eight cases, including the one of chorea, are given in the paper above referred to. His method of estimating the specific gravities seems to be the same as that adopted by Dr. Bucknill, and the same objections apply to the results as far as the cerebrum is concerned, and also with minor force to the estimation of the specific weight of the corpus striatum and optic * ' Glasgow Medical Journal,' No. I., 1853.