1. The reaction to small pieces of polyethylene and lucite in the subcutaneous tissues of 30 rats was studied at intervals up to three months after insertion. Polyethylene was shown to compare favorably in respect to minimum tissue reaction, with the well-tolerated lucite.
2. A series of clotting times was performed in polyethylene, paraffin, collodion and glass tubes. The clotting time in polyethylene tubes was about twice as long as in glass, and nearly as long as in paraffin and collodion-lined tubes. These data are similar to Hirschboeck’s findings for lucite tubes.
3. Clot retraction was found to be moderate and essentially similar in polyethylene, paraffin, and glass tubes. It was slight or absent in collodion tubes.
4. Capillary tubes of polyethylene were shown to repel water initially and then gradually to attract water over a period of days to a maximum height about one-half of that in glass tubes. Thus polyethylene follows Lampert’s rule, which states that the effect of a surface in delaying the coagulation of blood is proportional to the capacity of that surface for repelling water.
ACKNOWLEDGMENTS The authors wish to express appreciation to Drs. H. G. Saroff, J. Sendroy, Jr., J. L. Tullis, E. P. Cronkite, and Miss M. E. Tarver, for helpful advice and cooperation in these studies.