Q:

Could anybody identify the rank/regiment of this soldier?

Image of British soldier, probably taken in the late 1800s. Born in 1825, died in 1899.
Could you help me identify his rank and regiment?

A:

The uniform in the picture would seem to be that of an officer of a rifle brigade from the United Kingdom and not of a hussar as posited in another answer. This can be attested by the pouch belt chain lion worn across the chest. This item was worn, as far as I know, only by the officers of the rifle regiments/brigades. Furthermore, the style of embroidery and dull tint of the braid seems to align with the green jacket of the rifle brigade. Source: http://www.victorianstrollers.co.uk/stevesuniforms/riflecorps.html
As to the rank of the man pictured, it is hard to say. His sleeves and collar are relatively plain and thus would suggest he is not a particularly high ranking officer. Also, his only medal seems to denote a short or uneventful career despite his advanced age. Perhaps, he was simply a reserve officer in the London Rifle Brigade or some other reserve unit which didn't see much action before the 20th century.

