[Letter] 1890 Jul 7, The University, Glasgow, to Dr (John Ambrose) Fleming / William Thomson, [later Lord Kelvin. He has 'looked into the matter of contact electricity and the multicellulars', giving details of readings. Major Cardew showed him his multicellular [voltmeter] and got different readings. Thomson is going to investigate this difference but thinks it may be due to 'the varnishing of the aluminium needle'. 4p ts. on 1 leaf, holograph signed]