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SCIENCE 



[N. S. Vol. LIV. No. 1396 



stract journal were prefixed to eaeli original 

 article, a reabstraeting of the article would 

 be unnecessary and much duplication of efFort 

 would be avoided. Moreover the practise would 

 enable abstract journals to report current lit- 

 erature with less delay than at present. 



But to render this service to scientists, the 

 abstracts must, as stated above, adequately de- 

 scribe and summarize the contents of the 

 articles. The standard must not only be 

 high; it must be uniform, so that the ab- 

 stracts may be beyond suspicion of incomplete- 

 ness and inaccuracy. 



During 1920 the National Eesearch Council 

 devoted considerable attention to various ques- 

 tions relating to abstracts, such as: how they 

 might be improved in form so as to render 

 more eSective service; how the rules might 

 be made more definite and the method of prep- 

 aration more systematic so as to result in 

 more uniformly good abstracts. As a result 

 of study and experimentation a type of ab- 

 stract was developed which is believed to be 

 well suited to the needs both of abstract jour- 

 nals and of scientific journals with prelimi- 

 nary abstracts. 



Abstracts of this type, which are called 

 analytic ahstracts, have been appearing in the 

 Astrophysical Journal and, less consistently, in 

 the Physical Review since January, 1920. 

 Their main characteristics are illustrated in 

 the following samples. 



1. A new method of determining the atomic 

 weight of iodine. Marcel Guichard ; Ann. 

 chim., 6, 279-318 (1916) ; 7, 5^9 (1917). 



ABSTRACT 



Atomic weight of iodine. — The pentoxide 

 method used involves the preparation of I^Oj, 

 the decomposition of this anhydrid, and the 

 collection of the iodine by condensation and of 

 the oxygen by combination with pure copper. 

 The mean of five determinations is 126.915. 

 The article gives in voluminous detail the re- 

 finements employed to guard against error. 



Iodine pentoxide; preparation, purification 

 and decomposition with heat. — The results of 

 a thorough study are presented. As it was 



found impracticable to prepare it by direct 

 combination of I^ and 0„, the method adopted 

 was to oxidize I^ with fuming HNO3 and 

 subsequently expel free Ij and HNO3 by 

 heating to 450°. This was carried out in an 

 evacuated train which is fully described. 



Preparation of pure iodine. — Detailed di- 

 rections are given. 



Occlusion of oxygen hy glass, porcelain and 

 copper was studied in order to determine the 

 best material for the apparatus. 



2. On K. 8. magnet steel. K. Honda and S. 



Saito; Physical Review, 16, 495-500, De- 

 cember, 1920. 



ABSTRACT 



K. S. magnet steel W O.Jf-0.8, Co 30-JfO, 

 W 5-9, Cr 1.5-3 per cent). — This remarkable 

 new alloy steel possesses, when tempered, an 

 extremely high coercive force, 226-257 gauss, 

 and a strong residual magnetism, varying from 

 620 to 920 C.G.S. units for different specimens. 

 The effect of repeated shock was to reduce 

 these values by only 6 per cent. The hysteresis 

 curves for a magnetizing force of =tr 1300 

 gauss show for the hardened steel an energy 

 loss of 900,000 ergs per cycle. Tempering is 

 best effected by heating to 950° C. and quench- 

 ing in heavy oil. This treatment applied to 

 annealed specimens increases the Brinell 

 hardness number from 444 to 652 and makes 

 the microstructure finer grained. 



t 



3. The structure of the helium atom. Irving 



Langmuir; Physical Review, 17, 339-353, 

 March, 1921. 



ABSTRACT 



Helium atom models. — (1) Bohr's model is 

 unsatisfactory because it gives too great a 

 value for the ionizing potential and is not in 

 accord with some of the optical and mag- 

 netic properties of helium. Since the chem- 

 ical evidence suggests that each electron in 

 an atom has its own orbit, separated from the 

 other orbits but closely interrelated with them, 

 two new models are considered. (2) In the 

 douhle circle model the two electrons are as- 

 sumed to move in two circular orbits, separate 



