most of the old houses that were with triple brick were built with brick made on the premises.an exterior wall, an interior wall, and they used the cull brick for fill in the center. the brick are most likely fine and will be for a long time. the mortar is another story. it may be fine, but alot of those houses have deteriorating mortar now as the mortar was mixed there also. most of the time with an abundace of lime. it is supposed to cure for the first 50 years (maybe 30....i forget) and start a slow deterioration the following years. we have cut the joints out back 1/2-3/4" and pointed it up with new mortar which will most likely outlast our lives with a few minor pop outs from ice along the way. that is very very time consuming and very very costly. if you can't rake the mortar out with your fingernail you're probably ok. a few sandy grains would be ok but not alot of soft powder. as far as the bearing walls, most likely it would be any brick and the interior walls would more than likely be built stouter than any today. it was common to lay the joist, rafters ,what have you, right in the masonry and they should be fine as long as it was protected from water and/or bugs.