ABSTRACT: The ``good'' Boussinesq equation utt=uxx-uxxxx-(u2)xx admits solitary wave solutions for all wave speeds c, 0<|c|<1. These waves are known to be aymptotically stable for |c|>1/2. The linear asymptotic instability of these solitary waves is demonstrated for |c|<1/2 by establishing that there exist unstable modes of the variational equation around the wave solution. This is done by means of the Evans function, an analytic function on the right complex half-plane that vanishes somewhere if and only if the solution is unstable. The result follows from comparison of the Evans function near the origin with its asymptotic behavior. The explicit computations are sufficiently complex that symbolic algebra software is used.