350 



SCIENCE 



[N. S. Vol. XXXVII. No. 948 



The age distribution of the native white popu- 

 lation is somewhat different from that of the 

 negroes, probably chiefly on account of a lower 

 death rate among whites, tending to greater 

 longevity. There has apparently been a very 

 marked decline in the birth rate among negroes 

 in recent years, while there has been a gradual 

 but less marked decline in the birth rate of the 

 whites during each decade for a long period of 

 time. 



Negroes tend to marry earlier than the native 

 white classes; and, in fact, at all age periods the 

 proportion of married, widowed and divorced per- 

 sons, taken together, is higher in the case of the 

 negroes of both sexes than in the case of the 

 native whites of native parentage. 



There has been a marked change in the com- 

 position of the foreign-born population of the 

 United States during recent years. Natives of 

 northwestern Europe constituted more than two 

 thirds of the total foreign-born population of the 

 United States in 1900, but less than half in 1910, 

 while southern and eastern Europeans formed only 

 a little over one sixth of the total at the earlier 

 census, as compared with three eighths in 1910. 

 The Germans and the Irish particularly have fallen 

 off conspicuously in numbers, while the natives of 

 Russia — largely Russian Jews and Poles — Austria, 

 Hungary, Italy, Greece and other countries of 

 southern and eastern Europe have increased by 

 very high percentages, no less than 1,090 per cent, 

 in the case of natives of Greece. The natives of 

 Russia now rank second among the foreign-born 

 classes, and those of Italy fourth. 



The speaker answered inquiries of various mem- 

 bers as to simdry items, and these questions were 

 accompanied by brief statements contributing fur- 

 ther facts and explanations, but there was no 

 extended discussion. 



Wm. H. Babcock, 



Secretary 



THE ACADEMY OF SCIENCE OF ST. LOUIS 



At the meeting of the Academy of Science of 

 St. Louis on January 20, Mr. S. Bent Russell read 

 a paper on "Demonstration and Design of Appa- 

 ratus to Simulate the Working of Nervous Dis- 

 charges. ' ' 



Professor J. L. Van Ornum, of Washington 

 University, spoke on "Experiments on the Point- 

 ing of Pressure Tubes to Eliminate Velocity Ef- 

 fects in Water Pipes. ' ' 



Professor P. E. Nipher, of Washington Uni- 

 versity, communicated to the academy the results 

 of recent experiments which seem to indicate that 

 the strength of a steel magnet depends upon its 

 electric potential. The magnetic moment deter- 

 mined by the Gaussian method of deflection ap- 

 pears to be a maximum when its negative poten- 

 tial is somewhat less than that of the earth. 



The magnet consists of a single layer of steel 

 wire having a diameter of .022 of a centimeter 

 wound longitudinally on a hollow conducting cyl- 

 inder 30 centimeters long and 2J centimeters in 

 diameter. The needle acted upon by this magnet 

 is completely enclosed in a copper screen. A 

 mirror on the needle is observed through a glass 

 window covered with copper gauze of .1 inch mesh. 

 The needle is held in the magnetic meridian by 

 means of an ordinary magnet serving to balance 

 the deflection due to the wire filaments constitu- 

 ting the magnet to be tested. This magnet is 

 insulated and connected with either terminal of 

 an influence machine, the other terminal being 

 grounded. No disruptive discharges are permitted 

 to occur. 



When the magnet to be tested is connected with 

 the positive terminal of the machine the needle is 

 slowly deflected over an angle of about 4 minutes 

 of are in about one fourth of an hour. When the 

 magnet is disconnected the needle returns to the 

 zero position in about the same time interval. 

 This may be repeated many times. The magnet 

 becomes stronger while in contact with this ter- 

 minal. 



When connected with the negative terminal sim- 

 ilar efi^ects are produced, but the magnet becomes 

 weaker instead of stronger. 



When the magnet is freshly magnetized it does 

 not wholly recover its strength when it is enfeebled 

 by connection with the negative terminal, but it 

 approaches a condition of permanence when the 

 operation is repeated. 



This result is similar to the well-known fact that 

 the attraction between masses of matter depends 

 upon their electric potential. 



Professor Nipher suggested that plating the 

 steel wire, of which the magnet is composed, with 

 a film of non-magnetic matter is likely to lead to 

 results of great interest. 



G. O. James, 

 Corresponding Secretary 



St. Louis, 



January 24, 1913 



