Johnson, Matthey and Co., Ltd

The silver nitrite may be prepared as described in Section 11,50, 17. The product supplied by Johnson, Matthey and Co. Ltd., of Hatton Garden, London, E.C. 1, is satisfactory it. should be washed with absolute methyl or ethyl alcohol, followed by sodium-dried ether, and dried in an electrically-heated oven at 100 for 30 minutes (longer heating results in darkening on the surface) the substance should be kept in a vacuum desiccator until required. 

That supplied by Johnson. Matthey and Co. Ltd. gives satisfactory results. 

We thank N.S.E.R.C. for research grants, Johnson,Matthey and Co., Ltd. for a loan of ruthenium, and Professor E. Piers for several of the aldehyde substrates. 

We thank S. G. Murray and W. P. Griffith for useful discussions. We also gratefully acknowledge financial assistance by the European Office of the U.S. Army under the auspices of Grant DAERO-79-G-0033 and the loan of precious metal salts by Johnson Matthey and Co. Ltd. 

I thank Johnson-Matthey and Co. Ltd. for a loan of precious metal salts. The financial support of CNPq, Brasil and Simon Fraser University is acknowledged. Collaboration with Prof J Williamson on the trypanocidic properties of platinum complexes is especially acknowledged as is that of Prof. J.M. Goldie for the crytotoxicity studies. 

Information from Johnson, Matthey and Co. Ltd., 1944 the statement in Roscoe and Schorlemmer, TreatisCy 1923, ii, 1455, that the still was made by Johnson and Matthey is wrong, since Percival Norton Johnson did not start his business until 1817 and it did not become Johnson and Matthey until 1851. It was probably made by Wollaston, who made five large platinum boilers for concentrating sulphuric acid in 1805-18. 

Materials.—" Pure Platinum Sponge " was used as supphed by Johnson, Matthey, and Mallory Ltd., Toronto. Fluorine was taken directly from a cylinder supplied by Allied Chemicals New York and used after hydrogen fluoride had been removed by passing it over sodium fluoride. Halogen fluorides, from the Mattheson Co. Inc., Illinois, were given a preliminary trap-to-trap distillation. Selenium terafluoride was prepared according to Aynsley, Peacock, and Robinson s directions. 

For the spectrometric method, U.S. Geological Survey standard granite G-2 is used as a base for the standard. To 0.5 g portions of G-2 are added 379 mg of Specpure A1203 ( Johnson Matthey Chemicals Ltd., through Jarrell-Ash Division, Fisher Scientific Co., 590 Lincoln St., Waltham, Mass. 02154) to adjust the Si02 Al203 ratio to 3 1 and various amounts of a synthetic standard containing 1000 ppm (w/w) of each of... 

I am grateful to the Science Research Council for support, to Johnson Matthey, Ltd. for the generous loan of rare-metal salts, to my co-workers whose names appear in the references, and to W. S. McDonald for supplying the drawing for Figure 1. 

All solutions are made with deionized distilled water and are prepared from AnalaR chemicals (British Drug Houses, Poole, England) with the exception of the magnesium and calcium stock solutions. The calcium solutions are made from Specpure calcium carbonate (Johnson, Matthey Co. Ltd., London) dissolved in the minimum volume of concentrated HCl. The magnesium stock solution is prepared from Specpure magnesium sulfate. Polythene containers are used to store all solutions. 

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