Note on the formulas used for calculating the weight of the brain in the albino rats / by Shinkishi Hatai.

  • Hatai, Shinkishi.
Date:
1909
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Licence: In copyright

Credit: Note on the formulas used for calculating the weight of the brain in the albino rats / by Shinkishi Hatai. 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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    NOTE ON THE FORMULAS USED FOR CALCULATING THE WEIGHT OF THE BRAIN IN THE ALBINO RATS. BY SHINKISHI 1IATAI. Associate in Neurology at The Wistar Institute. In previous papers (Hatai, ’08; Donaldson, ’08) the formulas for calculating the weight of the brain and of the spinal cord in rela- tion to the body weight were determined on the assumption that the amount of increment to the weight of these parts is proportional to the reciprocal of the body weight plus a constant or <jy=h i 3x (x + a) (1) where y is the weight of the brain or spinal cord in grains and x the weight of the body in grams. Integration of (1) gives at once the value of y. Thus: y=h f (x +'a)dx = h log + a) + c or in our previous notation (Donaldson, ’08): y = A + C log (x + ft) (2) This type of logarithmic formula has been used by the present writer (’08) and Donaldson (’08) and was found to be very sat- isfactory for representing the relation between the body weight and the weight of the brain or spinal cord. This type was further employed by Donaldson (’09) to repre- sent the relation between the body weight and body length and was proved by him to be satisfactory. The Journal of Comparative Neurology and Psychology.—Vol. XIX, No. 2.