516 



SCIENCE. 



[N. S. Vol. XVII. No. 430. 



In low-tension secondary distribution, the 

 direct current from the converter being in- 

 troduced at the neutral points of the two dis- 

 tributing-circuit coils, the passage or interrup- 

 tion of th(3' current thus introduced has no ef- 

 fect upon the action of the alternating system. 

 A considerable variety of distribution, in de- 

 tail, has been found practicable with this sys- 

 tem, and the outcome of its adoption is ex- 

 pected to be a very considerable saving in 

 cost of line and in expense of both light and 

 power production.* It lends itself equally to 

 distributions in light and power systems and 

 to simultaneous operation of arc and incan- 

 descent lamps, giving a gain, often large, in 

 the cost of copper and of line, and simplifying 

 the whole scheme of transmission of electrical 

 energy to multiple forms of work. 



E. H. Thurston. 



BBAIN-WEIGET8 OF BROTHERS AND 



SISTERS. 

 Brain-weights of brothers and sisters are 

 not often obtained. When Professor Joseph 

 Leidy and his brother. Dr. Philip Leidy, died 

 within a few hours of each other, their brains, 

 examined under similar circumstances and by 

 the same observer (Professor Harrison Allen), 

 were found to weigh exactly the same, 45.5 

 ounces troy weight, or 1,415 grams. The 

 more distinguished of the two. Professor 

 Joseph Leidy, was also fourteen years older 

 than his brother. Marchand, in his recent 

 work on brain-weights, cites some interesting 

 figures from Professor Kockel, who had the 

 opportunity to remove and weigh the brains 

 of three brothers and of a brother and two 

 sisters. The figures follow: 



A. BKOTHEE AND TWO SISTERS, DEOWNED TOGETHER. 



Boy, age 44 years 88 cm. 1292 gms. 



Girl, age 34 years 83 " 950 " 



Girl, age 2 years 67 " 960 " 



B. THREE BROTHERS, SOTEOCATED BT ILLUMINATING 



GAS. 



Boy, age 124 years 133 em. 1400 gms. 



Boy, age 8 years 121 " 1460 " 



Boy, age 4i years 100 " 1400 " 



* For descriptions of some of these features 

 and of illustrative distributions see Trans. M. E. 

 and E. E. .Issoc. of Cornell Vniversiiy, February 2, 

 1903; Elect. World and Engineer, February 28, 

 1903; Electrical Age, March, 1903. 



It may be noted in the first instance that 

 the brain-weight of the two-year-old girl ex- 

 ceeds that of the older sister by 10 grams, 

 while the brother's, who was only 5 cm. taller 

 than the elder sister, exceeds her brain-weight 

 by 342 grams. In the second instance the 

 brain of the eight-year-old boy is 60 grams 

 heavier than that of the older brother, while 

 the latter's brain-weight is equaled by that of 

 the yoimgest brother. It should be added that 

 all three brains were exceedingly hyperffimic, 

 the venous channels were filled with much 

 blood, and the brain-substance generally was 

 moist and soft. The brains of adult brothers 

 and sisters are more desirable for comparison. 



E. A. S. 



HARVARD METHOD OF TEACHING 

 PHYSIOLOGY.* 



The new method of teaching physiology 

 proposed in the Boston Medical and Surgical 

 Journal, December 29, 1898, and more fully 

 explained in the Philadelphia Medical Jour- 

 nal, September 1, 1900, was adopted by the 

 Harvard Medical School in 1899. 



The traditional method of teaching physi- 

 ology consists of a systematic course of lec- 

 tures illustrated by occasional demonstrations. 

 For thirty years or more, especially in Eng- 

 land, this didactic teaching has been further 

 illustrated by certain experiments performed 

 by the students themselves. Laboratory ex- 

 periments, therefore, have long been a valued 

 part of the instruction in physiology in many 

 universities. When the new method of teach- 

 ing was introduced in the Harvard Medical 

 School, and two hundred students worked 

 daily in the physiological laboratories, it was 

 said that this was only doing in a large way 

 that which had been done in a small way for 

 many years. The enterprise was held to be 

 valuable because it showed that large num- 

 bers of first-year medical students could be 

 carried simultaneously through a long series 

 of experiments, many of which had been 

 thought beyond their powers; it was a lesson 

 in faith and an example of administration, 

 but nothing more. 



* From ' Physiology at Harvard,' by W. T. 

 Porter, second edition, January, 1903. 



