Several modifications in the use of n-butyl alcohol are suggested. These modifications include a revised series of dehydration solutions for exacting work, an abbreviated schedule of limited usefulness, and a simple method for more rapid paraffin infiltration. The use of a triangular coordinate graph may be valuable in designing dehydration procedures for special purposes. Changes in the primary fixation image are significantly less severe by dehydration with butyl alcohol than with many other reagents. Such deleterious effects may be further minimized by reducing the time and temperature factors to the practical limit and by substituting acetone for ethyl alcohol in a dehydration series such as that of Zirkle.