186S.] 441 [Wyman. 



other case, cubic contents converted into brain weight.* The method 

 proposed by Prof. Treadwell has an advantage in the fact that the 

 weight of a cubic inch of water (252.5 grains, or 1G.4 grams) has 

 been determined with great accuracy, and is a constant quantity; 

 while that of a cubic inch of sand varies according to locaHty, recjnir- 

 ing a fresh determination each time a different kind of sand is used. 



The nature of the material used for measuring the capacity of the 

 skull is imjiortant, but observers have had recourse to very diti'erent 

 kinds. Water would unquestionably be the best, but its use is im- 

 practicable owing to the great difficulty in making the cranium sutfi- 

 cienrly tight to retain it. The late Dr. Samuel George Morton, 

 having used white mustard seed "on account of its spherical form, its 

 hardness, and the equal size of its grains," afterwards, at the sugges- 

 tion of ]Mr. J. S. Phillips, substituted No. 8 shot which he found to 

 give much more precise results, and with these all the measurements 

 recorded in his tables were made.f Sir William Hamilton sharply 

 criticises Dr. Morton's method as "only a clumsy and unsatisfactory 

 imitation of mine," asserting that "pure silicious sand was the best 

 means of accomplishing the purpose, from its suitable ponderosity, 

 incompi'essibility, equality rf weight in all weathers, and tenuity, "f 

 Dr. J. Barnard Davis, whose practical knowledge of the subject 

 makes his opinion worthy of high consideration, also reconunends the 

 use of fine sand, § but instead of measuring he weighs the quantity 

 the skull holds. Having ascertained the cubic measure of an ounce 

 of sand, the whole quantity is readily converted into cubic inches, or 

 by making a correction for difference in specific gravity, into brain 

 weight. Various other substances, such as peas, flax seed, rice, etc., 

 have been used. Welcker recommends the grains of husked wheat. 

 For a full account of these and of the different methods of comparing 

 crania, the reader is referred to the valuable and instructive memoir 

 of Dr. J. Aitken Meigs, on the Mensuration of the Human Skull. || 



From the following table, the result of careful comparative experi- 

 ments, it will be seen that, for exactness, shot are tar preferable to 

 sand, and that Sir W'illiam Hamilton's criticisms are unjust. The 

 chief requisites for a good material for measuring crania, are lightness 

 and uniformity in the size of the particles or component bodies; the 

 s'ze should be such that they will not escape from the foramina in 

 the orbit, and their shape such that they will occupy the smallest 



* American Journal of Medical Science, in the account of tlie last illne.ss of the 

 Hon. Daniel Webster, January, 1853. 

 t Crania Americana, p. 253. 

 + Op. cit. Vol. I., p. 240. 

 § Crania Britannica. 

 • II Korth American Med. Chirur. Review, Sept. 1861, p. 837. 



