A Convenient Retractor for Use in Operations and Dissections of Small-sized Animals.

In this apparatus a piece of paraffined twine passes from the cork float a to the bottom of the reservoir, then through a stationary tube b, and is fastened to the dripping unit d. The dripping unit d descends at the same rate as the level of the solution in the reservoir, since it takes up the slack of the cord which leads from the float a. The descent of the dripping unit is made possible by a rubber tube connection c, bearing