AN increase in lipolysing activity of the blood has been recorded in some patients after injury of adipose tissue^1,2. This increase is found to begin about three days after wounding. In the course of an investigation of the source of this lipase, we examined lung as well as adipose tissue, since lung is involved not only in the early complications of â fat embolismâ , but also in â systemic fat embolismâ , the signs of which appear after three days.