1. Zur Jod-Additionsmethode;Wijs;Ber. d. deutsch. chem. Gesellsch.,1898
2. All the reagents used except the potassium iodide solution were prepared according to the federal specification for varnish and shellac, No. TT-V-91a (Washington: U. S. Government Printing Office).
3. Potassium iodide free from iodate, 100 Gm., dissolved in distilled water and diluted to make 1 liter. Fresh solution must be employed, since iodide solutions are readily oxidized on standing to form free iodine.
4. Soluble starch, 5 Gm., dissolved in 500 ml. hot water containing 1 Gm. salicylic acid.
5. Inhibitor-free monomer was prepared for these experiments by distillation of the inhibited monomer at pressure of 9 to 10 cm. mercury. The middle fraction was used for the sample. Five milliliters of the middle fraction was pipetted into chloroform and diluted to make 1 liter. This solution was stored in a refrigerator to avoid any possibility of polymerization.