In fact the document is available on Genes Reunited. It says,

The Fiftieth Regiment of Foot

Wherof General Sir James DUFF Kt is Colonel

THESE ARE TO CERTIFY

THAT Private Matw NORRIS born in the Parish of Lynhum in or near the town of Chippenham in the County of Wiltshire was enlisted of the aforesaid Regiment at Kilkenny in the County of Kilkenny on the third day of April 1803 at the age of twenty three years for unde??????? Service.
That he hath served in the army for the space of seventeen Years and 202 Days after the Age of Eighteen according to the subjoined

STATEMENT OF SERVICE

Fencible Fusiliers, 3 April 1801 – 2 April 1803, Private, 2 years
50th Foot, 3 April 1803 – 21st October 1818, Private, 15 years 202 days

That in consequence of epilepsy

HE IS HEREBY DISCHARGED

That he is not to my knowledge, incapacitated by the Sentence of a General Court Martial from receiving Pension

That his General Conduct as a Soldier had been good.

Signed by Matthew NORRIS [in a confident hand] to confirm he has received all pay and arrears due.

To prevent any improper use being made of this discharge , by its falling into other Hands, the following is a description of the said Matthew NORRIS. He is about thirty nine Years of Age, is Five Feet six Inches in height, Brown hair, Grey eyes, Fair Complexion and by Trade or Occupation a Labourer.

Awesome! I now have moved back two generations. I can't thank you enough. I also checked on the Wiltshire "Moonrakers", and found it very interesting. It reminds me of the Poldark series. Looking forward to spending time in England and Wales.