New developments in ferromagnetic materials. - Journal of Chemical

New developments in ferromagnetic materials. Laurence S. Foster. J. Chem. Educ. , 1948, 25 (6), p 360. DOI: 10.1021/ed025p360.3. Publication Date: Jun...
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JOURNALO F CHEMICAL EDUCATION development and three others are devoted to sensitometry. One chapter discusses the structure of the developed photographic image, granularity, resolving power, and related topics. There is also a short chapter an sensitizing and desensitizing dyes. One page is given to dye coupler development but color photography is not included in the book. Neither is there sny discussion of reduction, intensification, or toning. This is not a book for light reading but it is well written, interesting, and rewarding. Briefly and clearly it presents the theory of black and white photography in about one-fourth the space used by Mees and bridges the internal since the larger book was published. JAMES C. MCCULLOUGH O s s n ~ mC o m ~ o n O s m m ~ 0x10 ,

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VEILIGHEID EN CHEMIE (Safety end Chemistry)

Ir. H. A. 1. Pieters, Director of the Central Laboratories of the

State Mines in Limburg (Holland). Published by the Safety Council of the State Mines, Heerlen, 1947. vi 306 pp. 41 figs. 35 tables. 14 X 22 cm. Paper-bound.

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Tms handy volume of directions for promoting safety in chemical laboratories is the revised and enlarged edition of a safety booklet issued in 1942 by the Dutoh State Mines and sold a t cost to the personnel of chemical and industrial labortttories. The subject matter is discussed in five chapters under the headings: (1) Hseards in Dealing with Glass, Gases and Inflammable or Explosive Materials, (2) Physiological and Toxicological Dsta on the Inorganic and Organic Substtanma Most Frequently Met in Chemical Laboratories, (3) Safety Appliances, (4) Directions for Promoting Safety in Handling Apparatus and Chemicals, and (5) Determination of Minute Quantities of Toxic Gases and of Dust Particles in Air. The treatment is thorough and detailed and includes recent improvements in experimental technique. The literature references at the end of each chapter cover the field thmugh 1947 and the tables a t the end of the book supplement the &ta in the text. Additional useful items are "the care and treatment of platinum ware" and alist of safety slogans (some of them in the original version), culled from the "National Safety News" for 1947. One might wish that the author had included a few striking "Safety posters," such as have been issued in this country, to teech proper respect for the hazards of chemicals. This omission, however, does not detract from the merits of this up-to-date voliume which deserves a wide circulation. H. 8. RnnsseGmn PormmEcanlc I ~ m r r u m T a w . NEWYon=

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KLOOSTER

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THE TECHNOLOGY OF ADHESIVES John Delmonte, Technical Director, Plastics Industries, Technical Institute, Los Angeles, California. Reinhold Publishing Cop., New Y o 4 1947. 516 pp. 79 figs. 100 tables. 15 X 22 cm. $8.

INTHE light of other publications on adhesives in the past twenty yeam, this book is very superior and the author is to be commended upon it. Not only does it cover the almost innumerable new synthetic adhesives that have appeared to take a large fraction of the field but its stvle is flowine: - and easv, .. with claritv of expression. The opening chapter gives an introduction to the subject of adhesion, with classification of adhesives. Following this there are wellwritten ctiapters on phenolic resins, urea and melamine resins, other thermosetting resins, polyvinyl resins and polystyrene and acrylic resins, with emphasis upon their use ag adhesives. In these several chapters much attention has been given to the synthesis of the resins under discussion, and the hook can be regarded as a good introduction to the chemistry of synthetic res-

ins and plastics. Perhaps there has been more space devoted to synthesis of these adhesives than is justi6ed in view of the good reference books available on the subject. Further chapters deal with rubber adhesives, adhesives from cellulose. from rotei ins and from other natural sources. While ~~~~. t l w trca1n1mt is noncritical, copious n.fcrmrrs are givrr. at the rnddof thc ehnptcrs which make thid book aqdvndid hildiographic sourrr. It is to be hoped tlat sonwlirnr a truly critical rrvien of t l e many patentsand litcrnturcclairr~ssill b v m c avallxl,le. .\ wry wrlron~ccl.aptcr oi thirty paw9 un t h r o n ~ irfadhtsivc s arrion is included. I:ndoul~tcJly o w of the wcakesr aqwcts of thc sul,jtrt oi ndlk~ivcsid the throrrticsl barkrrou~~d, and the reviewer feels that even more emphasis could hive heen placed on theory to advantage. One hundred and twenty pages follow on adhesives for wood, plastics, rubber, paper, etc., giving general considerations sometimeslackingindetail that one would need for the solutionof specifieproblems. For example, it is mentioned that different woods vary widely in their ease of gluing, but no mention is made of which woods glue easily and which poorly. On this account, the book cannot be regarded as of maximumvalue to theshopman. The final chapter gives details on tests and specifications for adhesives. 'l'ypography and qunlity of illusuationa urc p o d . Curnpnrstiwly f e r r rypograpl.ical crrurs 1m.c bccrr fw1111nnd 0111y a very occnriod rnislnrcrprctnrion of fa% In gcrreml, rhc hook ran he highly recommended. ~~

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8. S. KISTLER

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NEW DEVELOPMENTS IN FERROMAGNETIC MATERIALS

!L. Snoek, Philips Gloeilampen Fabrieken, Eindhoven-Holland. Elsevier Publishing Co., New Yo*, 1947. viii + 136 pp. 15 X 21 cm. 13 tables. 52 figs. $2.50.

T m s s d booklet is nineteenth in a series of Monopaphs on the Prooress of Research in Holland Durino the War. ouhlifihed t,n "show tllr world thsc scientists in t l NctLerlmJs ~ haw n rnnined arrive during the irvc years of Gcrma~rw:ru~~nrion." In tl,c introduction, the aurhor admits the limited swpe uf rlw book nnd points out that "it is intended as a report on our researches during the wax under conditions which beeame gradually harder and in an atmosphere ill suited to the development of scientific thought." I t is primarily addressed to physicists interested in the theory of ferromagnetic hysteresis. Chemists will, nevertheless, lind much of interest in the third and final chapter an, "Development of Magnetic Materials," which deals particulrtrly with ferromagnetic nonmetals, especially those that may be considered analogous of magnetite (Fea03. These are given the type name of "ferroxcubes" with the general formula, MO.FelOs where M = Mg, Zn, Cu, Ni, Fe, Go, and Mn. They have a cubic structure and form continuous series of solid solutions. While showing lower saturation values than ferromagnetic metals, they have the advantage of being virtually nonconductors and show low hysteresis and very low eddy-current losses a t high frequencies. "Numerous applications of these magnetic oxides are possible in radio land telephony." To produce these interesting materials, powder metallurgy or ceramic techniques are employed. The most favorable high frequency properties are observed when the products contain no oxygen deficiency and have a dense structure; these properties are attained under conditions of sinterine that insure eomolete reartian hrtwlrm wlid cwnponcntsat lowcit possible tempernturcs. 'Chr n.ork desrrihcd in Chaptcr 3 would w n c ahirrrhlg ns a topic for a srminxr irr 'ulvanvcd iuorganic clrcnlistr.~.

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LAURENCE S. FOSTER Wmemowr* A ~ ~ E N A L W a ~ s n ~ o wM n ,~ s s * c m n s ~ ~ ~ s