1. On the structure of amethyst and its genesis in nature

   • C. V. Raman
   • A. Jayaraman

   OriginalPaper Pages: 221 - 229

2. The flux of primary cosmic ray nuclei of atomic numberZ⩾2 at geomagnetic latitude 30°

   • B. Peters

   OriginalPaper Pages: 230 - 248

3. Synthetic experiments in the benzopyrone series

   • A. C. Jain
   • T. R. Seshadri

   OriginalPaper Pages: 249 - 259

4. Studies of gallic acid complexes with metals and their analytical applications

   • Ch. Venkateswarlu
   • M. Sankar Das
   • V. T. Athavale

   OriginalPaper Pages: 260 - 269