Experimental study of children : including anthropometrical and psycho-physical measurements of Washington school children, and a bibliography / by Arthur MacDonald.

  • United States. Bureau of Education.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Experimental study of children : including anthropometrical and psycho-physical measurements of Washington school children, and a bibliography / by Arthur MacDonald. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    MEASUREMENTS OF TUB CRANIUM. The measiiremeuts of tbe crauiaui are perhaps the most imi)ortant, as it iucases the braiu. It is also i^robable, for the same reason, that defects of the crauium are more significant than those in other jDortions of the body. It is sometimes said that in general the nearer a ijhysical defect is to the brain, the more significant it is. In tliis connection it may be mentioned that a high palate is a frequent aceomiianiment of mental feebleness—a sign of congenital defect. The two most common measurements of the head are its maximum length and maximum width. In order to compare the length and breadth con- veniently the width is multiplied by 100 and divided by the length, giving the cephalic index, which is one of the most i^iG. 1. Callipers (Broca). important measurements in anthropology. When this index is 75 or less the person is considered long headed or dolichocephalic; Avhen it is more tlian 75 and less than 80 the head is called medium or mesocephalic, and when the index is from 80 to 85, inclusive, the individual is said to be broad headed or brachycephalic. The instrument used to measure the head is the callipers, represented in fig. 1. SENSIBILITY TO HEAT. There have been found on the body what are called temperature sjyots (Goldscheider and Blix). They are arranged in lines or in chains; thus in fig. 2 are represented the cold and warm spots of the upper side of the forearm. The temperature sense seems to have special cold nerves and warm nerves which blend with the nerve of touch; thus specific cold and warm sensations are felt at points or areas on the skin which corre- spond to the ends of the temperature nerves. This extends the doc- trine of the specific energy of the senses. The least sensibility to heat was determined by the thermaisthesio- meter of Eulenburg (fig. 3). This is an instrument consisting of two thermometers fastened together, as seen in the figure. The electrical arrangement for chang- ing the temperature of the instrument was not employed. The left- hand thermometer (A) w^as heated until it registered about 10° higher tem])erature than the right-liand thermometer (B); then the two ther- mometers were placed on the palmar surface of the wrist in a line at