A PARTICULAR FORM OF FRACTURE OF SKULL. To the Editor of "The Indian Medical Gazette." gIR _jf a rifxid bar be fixed upon a wall by one of its end, and if more and more heavy weights are gradually placed 011 its free end,' the bar will ultimately break at the fixed point will happen if a sharp and heavy in the wall The same thing blow is struck 011 the bar. By the principle of lever, the more this effect of the blow or of the weight will be greater, the bar, than the fixed end. This is nearer to the free end of will a explain particular well-known mechanical principle form of fracture in a definite region of the skull. ot a parietal bone which rests The anterior superior end below the frontal bone is somewhat in the position of a bar fixed at one end and free at the other end. More correctly of the separate parietal bones speaking, as the two such ends at the sagital suture and are interlocked by firm indentations as resembling the free they should be considered together portion of a rod fixed at the base. This comparatively free becomes fixed at the point, when portion of the parietal bone the parietal bone begins to rest upon the frontal bone instead blow of sufficient force is struck of supporting the same. If a this comparatively free and movable portion of the on parietal bones the line of fracture tends to pass through the bones noted above, so that two two fixed points of the p metal triangular pieces are broken off from the anterior and inner According to the principle margins of the parietal bones. blow in breaking off the pieces of of the lever the effect of a is situated nearer the anterior bones will be greater more it I have seen this to happen actually end of the sagital suture. a P.-M. examination describof notes in some cases, and the has been published in the August ing above kind of fracture Gazette giving the summary number of the Indian Medical medical section of the Asiatic of the papers read before the the two anterior and inner case Society Bengal. I11 this bones were broken off, in the ends of each of the parietal 1* inch form of two isosceles triangles having the sides about fissures in the unbroken portion of long and there were a few at somewhat right angles to the the parietal bones starting the blow struck was almost at the line of fracture In this case The occurrence of the fissures very end of the sagital suture. resembled what happens when a marble is struck on a pane the lines of fissure begin at the of glass. In this last case the portions of the glass point struck and extends towards fixed. Something like the above which are comparatively happened in this case also. 1 ours, etCi ^ ! b A HAST LAL SARKAR, Arumbagh. Assistant Surgeon. [This is an amplification of the brief note on this fracture given in a recent report of the Asiatic Society, Medical Section.?Kd., I. M. (??] ?