Sample Source ID of a Jel hip hop track

Hi, this is just something that i've been curious about for ages.
On Jel's Greenball album, there's two interludes which seem to be sampled from an old blues/soul track. The tracks on Jel's album are 'In Fact' and 'Mother May I'. I've uploaded the track 'In Fact' to: http://s27.yousendit.com/d.aspx?id=3EGP2MXJ85E461KM3U6VHIEYT0
in the hope that someone might recognise it and is able to tell me the name of the original song!
Thanks in advance.