nice ▁are ▁simplified ▁versions ▁of ▁the ▁ones ▁on ▁the ▁original ▁block . ▁Rec essed ▁metal ▁pan els ▁tie ▁the ▁eight - p ane ▁metal - fr amed ▁cas ement ▁windows ▁on ▁the ▁first , ▁second , ▁and ▁third ▁levels ▁into ▁the ▁same ▁kind ▁of ▁vertical ▁grouping ▁found ▁on ▁the ▁original ▁building . ▁There ▁are ▁two ▁simple ▁double ▁entrance ▁doors ▁at ▁the ▁bas ement ▁level ▁on ▁the ▁west ▁elev ation . ▁There ▁is ▁a ▁loading ▁dock ▁in ▁the ▁full - height ▁bas ement ▁level ▁at ▁the ▁south ▁end ▁of ▁the ▁addition . ▁ ▁History ▁ ▁Building ▁ 4 0 ▁was ▁home ▁to ▁the ▁four ▁success ors ▁to ▁the ▁Army ▁Medical ▁School : ▁the ▁Medical ▁Department ▁Professional ▁Service ▁School ▁( 1 9 2 3 - 1 9 4 7 ), ▁the ▁Army ▁Medical ▁Department ▁Research ▁and ▁Gr adu ate ▁School ▁( 1 9 4 7 - 1 9 5 0 ), ▁the ▁Army ▁Medical ▁Service ▁Gr adu ate ▁School ▁( 1 9 5 0 - 1 9 5 3 ), ▁and ▁finally ▁the ▁Walter ▁Re ed ▁Army ▁Institute ▁of ▁Research ▁( 1 9 5 3 - 1 9 9 9 ). ▁In ▁ 1 9 9 9 , ▁W RA IR ▁re located ▁to ▁its ▁present ▁Forest ▁Glen , ▁Maryland ▁site . ▁ ▁One ▁of ▁the ▁earliest ▁nuclear ▁react ors ▁in ▁the ▁United ▁States ▁was ▁installed ▁in ▁the ▁bas ement ▁of ▁the ▁building ' s ▁addition . ▁The ▁re actor ▁was ▁de comm ission ed ▁in ▁the ▁late ▁ 1 9 7 0 s .