24 



SCIENCE, 



[N. S. Vol. IX. No. 210. 



In the case of nickel this was done in 

 order to emphasize the difference between 

 the atomic weights of cobalt and nickel, 

 although in both values there may be 

 possible deviations of ± 0.2. The true 

 atomic weights of bismuth and tin are not 

 correct to a certainty, to within 0.1. The 

 value of hydrogen is 1.008, correct to witliin 

 0.001, but the approximation of 1.01 has 

 been regarded as permissible for the re- 

 quirements of practice, as it involves an 

 error of only one-fifth of one per cent. The 

 values given for the elements marked in 

 tlie table with interrogation points are not 

 necessarily exact within whole units of the 

 atomic weights assigned. 



Ferdinand G. Wiechmann. 



JOHN CUMMIKGS. 

 In the decease of Hon. John Cummings, 

 of Woburn, Mass., on the 21st of December, 

 there terminated a life whicli has been note- 

 worthy for the encouragement it has given 

 to the study and teacliing of science. In 

 the early part of his manhood days Mr. 

 Cummings acquired a reputation for honor- 

 able dealing and for his success in the 

 manufacture of leather in his native town 

 of Woburn. To that town he was always 

 loyal and generous, but his intelligence and 

 his activity led him into larger circles until 

 he became favorably known and his influ- 

 ence was felt in a large and populous com- 

 munity. He became acquainted with the 

 late William B. Eogers, for whom he al- 

 ways cherished an admiration and a pro- 

 found regard. He also knew Louis Agassiz, 

 Jeffries Wyman, Asa Gray and others, and 

 he soon became a student as well as a lover 

 of nature. The ofBces of trust and of busi- 

 ness responsibility which he filled make a 

 long and notable list, but his large affairs 

 did not prevent him from cultivating a love 

 for science, and they aided him in multi- 

 plying his gifts to the cause of education. 

 Through his attachment for William B. 



Eogers he was interested in the founding of 

 the Massachusetts Institute of Technology, 

 and he became one of its most substantial 

 supporters, contributing to its financial 

 needs and serving as its Treasurer for 17 

 years. It was through his generosity that 

 the Boston Society of Natural History 

 started its ' Teachers' School of Science,' 

 and it was through his liberality that its 

 botanical collection was developed and that 

 it has i-eceived special care to the present 

 day. He was actively and generously in- 

 terested in the work of public instruction, 

 and he extended his aid to the South after 

 the close of the Civil War. In one instance 

 he purchased a building and supplied teach- 

 ers, urging them to work for the estab- 

 lishment of free public schools, and when 

 this was about to be accomplished he do- 

 nated the building to the cause. His gifts 

 and his efforts were never calculated to at- 

 tract attention to himself, and many of his 

 good deeds were scarcely known even by 

 his friends. He was one of a class of honor- 

 able and broad-minded business men who 

 have been magnanimous in their support of 

 science education, and who have found time 

 to participate in the acquisition of knowl- 

 edge, while aiding others to means for the 

 prosecution of their studies or investiga- 

 tions. 



Wm. H. Niles. 



SCIENTIFIC BOOKS. 

 Matter, Energy, Force and Work. By SiLAS 

 W. HoLMAN, Professor (Emeritus) Massa- 

 chusetts lustitute of Technology. New 

 York, The Macmillau Company. 

 Lovers of exact science are already indebted 

 to Professor Holman for numerous important 

 contributions to our knowledge of physics and 

 especially for valuable suggestions as to the 

 best treatment of the experimental solution of 

 physical problems. His most pretentious work 

 thus far is that on ' Precision of Measurements, ' 

 which is everywhere recognized as a standard 

 and which ought to be in the hands of every 



