RT Journal A1 NARAT JK, CHOBOT G T1 EFfect of sclerosing substances on healing of fractures JF Archives of Surgery JO Archives of Surgery YR 1939 FD August 1 VO 39 IS 2 SP 264 OP 268 DO 10.1001/archsurg.1939.01200140096008 UL http://dx.doi.org/10.1001/archsurg.1939.01200140096008 AB It is not within the scope of this paper to discuss the causes of delayed union or nonunion of fractures. It may be briefly mentioned that local as well as constitutional factors come into consideration and that in spite of careful attention to these conditions frequently no union can be obtained. The field for an efficient stimulant of regeneration of bone is open.While the humoral theory of osseous growth finds numerous proponents, another school of thought is gaining popularity; this school teaches that bone is formed by direct action of specific cells. Although the problem is still awaiting solution, the cellular theory is supported by the results of many experiments and by many clinical observations. It is possible, therefore, that a stimulant of osseous growth which can be used in selected cases of nonunion or delayed union may be found. Such an agent must fulfil the following conditions: (1)