1868.] 



in the different Races of Man, 



237 



doubt internal capacities themselves become a legitimate means of com- 

 parison. 



Synostotic and artificially deformed skulls are m.ostly included, for the 

 reason specified, that their internal capacities are usually not materially 

 interfered with. 



Morton also failed to distinguish the sexes, and his Tables give no 

 indication how many of the skulls were those of men and how many those 

 of women. When we recollect the great normal diversity in the size of the 

 brain in the two sexes in any given race, this omission becomes of serious 

 importance. In the series of skulls now examnned, this diversity in the 

 weight of the brain in the two sexes extends from less than 10 per cent, to 

 something more than 12J per cent. ; so that Prof. Welcker's datum of 10 

 per cent, is tolerably correct. In our measurements the sexes are marked, 

 and adult examples only included. All the crania have been carefully 

 and as uniformly as possible filled with dry Calais sand of a definite specific 

 weight, which has been afterwards weighed and then reduced to its equiva- 

 lent in cerebral matter of 1040 specific gravity, after the deduction of 

 the 15 per cent. The observations on the weight of the brain in all the 

 races have been arranged in seven Tables, corresponding very nearly to the 

 races of the great divisions of the globe. The' results show that Prof. 

 Tiedemann was misled when he hastily assumed that, inasmuch as a 

 certain size and mass of brain was an essential condition for the exercise of 

 the faculties of the mind, all human races are furnished therewith in an 

 equal degree. 



One important object has always been kept in view — namely, a careful 

 comparison of the calculated observations of the Tables with the actual de- 

 terminations of those who have weighed the brains of different races, as far 

 as such determinations have extended. This has been done with the view 

 of comparing and correcting our results. 



It would be difficult to give any intelligible abstract of the Tables which 

 accompany the memoir. Of the notes to these Tables some short account 

 may be given here. 



Dr. Peacock and other excellent and careful observers pretty nearly coin- 

 cide ill the conclusion that the brain of EnglisJimen, on the average, is about 

 49 oz. av. in weight, or 1389 grammes. Dr. Robert Boyd, in his memoir in 

 the Philosophical Transactions, states as the result of his vast experience, that 

 the adult male brain among the insane varied from 48"17 oz. to 43*87 oz. ; 

 among the insane women from 44*55 oz. to 40*55 oz. ; whilst in the sa7ie 

 adults the averages varied in the 7nen from 48*20 oz. to 45*34 oz., and 

 among the ivomen from 43*70 oz. to 39*77 oz. It thus appears that Dr. 

 Boyd's investigations bring out an average brain-weight among the 

 English of, speaking roundly, about 5 oz. less than Dr. Peacock's means, 

 and rather more than 3 oz. less than our means. Dr. Thurnam, who ex- 

 amined and weighed the brains of 257 insane men and 213 insane women, 

 agrees in his results with Dr. Boyd, being still rather below the averages 



