title: Police examine three envelopes at Scottish parliament, one thought to contain white powder: source
text: EDINBURGH (Reuters) - Three similar envelopes, one believed to contain a suspicious white powder, were being investigated by police on Tuesday at the Scottish parliament, a source at the building said. The letters were addressed to Conservative lawmakers, Jamie Halcro Johnston, Liz Smith and Edward Mountain, the source said. One of the letters was only intercepted when opened by a researcher on the first floor of building while the other two letters had similar writing.  