PREFATORY NOTE TO THE SPECIAL NUMBER.

THE researeh papers published in the Jast twenty years by Sir C. V. Raman and the collaborators in bis laboratory during the period of his Professor- ship include over 600 titles, and the topics with which they deal indieate an astonishing catholicity of scienti¡ interests. The investigations concern themselves with subjects so diverse as the dynamics of vibrations and sound, the theory of musical instruments, speeial diffraetion problems, meteoro- logical and colloid optics, X-ray diffraction in liquids and solids, magnetism and magne-crystallie aetion, electro and magneto-opties, photo-elastieity of solids and fluids, dieleetrie behaviour, and ultra-sonics. In all of these subjects, the researehes of the school have notably influenced eurrent progress. I t is not possible within any reasonable timits of space to review them even in broad outline.

By lar the best-known work of Sir C. V. Raman is bis diseovery early in 1928 of the new radiation ef[ect known by his name and which was the natural culmination of the invesfigations on the seattering of light syste- matically earried on in his laboratory since 1921. The ten years which have elapsed since the discovery of the effeet have witnessed the fnlfilment of the confidently expressed hope of the diseoverer that ir wotfld throw new light on many problems in Physies and Chemistry. A great volume of literature has grown up round the subject, but the possibilities of further advanee are as great as ever in respect of both the physical and ehemieal applications.

The Council of the Aeademy felt that ir would be desirable in some way to signalise the completion of ten years' international collaboration and research on the Raman effeet. Aeeordingly, in inviting eontributions to this Special Number, they indieated the scattering of light, the Raman effeet and related topics as the preferred subjeet. To the several distinguished contributors from outside India who have generously responded to the invitation to contribute to these Pro:e,dings in spite of the very short notice given and who have helped to make this Special Xumber a truly international effort, the Council of the Aeademy tender their grateful thanks. In honouring Sir C. V. Raman and the Academy by their contributions, the authors have also helped to advanee the cause o[ seienee, for there can be little dottbt that the perusal of the contents of this volume will inspire new efforts in this field of research in many eountries.

1V[essages eonveying good wishes and felicitations have been reeeived from many distinguished men of seienee including the contributors to the

249

250 Prefatory Note to the SŸ Number

volume, as also severa1 others who owing to shortness of notice or other cause were unable to send formal papers, namely Professors C. G. Darwin, W. Iffeisenberg, G. 3~ie, W. Pauli, J. C. Slater, A. Sommerfeld and II. C. Urey. Professor K. W. F. Kohlrausch of Graz, besides forwarding ten original eontributions which appear in this volume, has sent a message whieh is reproduced below.

B. S. ~.

SEItR CIEEHRTER HERR,

Anl i egend f lnden Sie zehn A r b e i t e n aus d e m Gebie te des " l ~ a m a n - E f f e k t e s ", die das P h y s i k a l i s c h e Ins t i tu t , der T e c h n i s c h e n Hochschu le Graz als k l e inen Bei~rag zu d e m S i r Venka~,~ R u m a n g e w i d m e t e n F e s ~ b a n d de r " P rocee~ ings " zu i ib~r re ichen die E h r e ha t .

I r a D e z e m b e r 1928 w u r d e n a h dies~m I n ~ t i t u t e die e r s t e n R a m a n - S p e k b r e n a u f g e n o m m e n ; die dama l s in BebLieb gese tz te A p p ~ r a t u r h a t bis h e u t e 2775, die i ib r igen a l l m a h l i c h h i n z u g e k o m m e n e n A ppa ra~u ren h a b ~ n r u n d 700 A u f n a h m e n gel iefer t . Die Messungs -Ergebn i s se w u r d e n ira e t w a ]50 P u b l i k a ~ i o n e n verwert~eb; d a r u u t e r w a r e n sechs Disserbabionen, drei t t a b i l i t a t i o n s schrif~en, zwei b ª

Sei~ ]0 5 a h r e n l iegen die Arb3i tz ie le de r Ins~itu~es fas~ ausschl iess l ich ~uf d e m G e b i e ~ de r m o l e k u l a r e n Schw i ngungs spekt, ren, also au f e i n e m Gebie te , das ers6 d u r c h die E n t d e c k u n g des " R a m a n - E f f e k b e s " wi rk l ich zugang l i ch g e m a c h t wurde . Es is5 k a u m ~bz~h lba r , wie ofb in d iesen 10 Yahren der N a m e " R a m £ " ausgesp rochen u n d wiede rgesch r i eben wurde.

Dass das Ins~ibug und ~lle saine A n g e h 5 r i g e n j e n ~ m l~anne , de~sen Genie es die M6gl ichke i t zu d iesem z e h n j ~ h r i g e n inLens iven Arbe i t sbe~ r i eb ve rdankb , au f r i ch t i ge H o c h a c h t u n g u n d V e r e h r u n g e n t g e g e n b r i n g Q isb selbsLverst~,ndlich. I ch m a c h e m i c h z u m Spreche r ~ller Grazer Nª se iner EnLdeckung , w e n n ich in i h r e m u n d in m e i n e m e i g e n e m N a m e n Sir V e n k a t a R a m a n zu se inem f ª Gebiirbs~age au f das he r r l i chs t e begl i ick-wª

K. W. F. KOItLRAUSCtt.