256 SIR M. MACKVVKÏS UjN llift .kuIjK.. ur inn iaiuww nm,«».i however, a thickening ot' the shaft at one part, and it was considérée! probable that the silve'r ring lay underneath. The bone was scraped through in a vertical direction and after penetniting the bone for about-one-eighth of an inch tlie silver ring was exposed,' Completel v bnried in rirni osseous tissue. Three otlier apertures were scraped through at différent parts of the circumference of the shaft so as to 'expose the silver ring at each.
Tlie thiekness of the new bone covering the ring in front was fully one-eightb of an inch and it was a Httle les* hehind. Thus the silver ring placed upon the .bone dennded of periosteum had in three months become
1 j 1 11'1." lt.a 1.o ~n_n~rc~f:t ~ni~~
completel y enveloped in newly-formed bone one-eighth of an inch in thiekness..
The shaft operated upon is smaller in circumference than its fellow in left limb, the diminution in-bulk being apparent at tlie part which was denuded of periosteum, but the new bone at this part is denser than that on the other parts of tlie shaft whicli were Mot operated on.
Though- the results attained in this expei'iment-pointjed ̃ in the direction that thé bone produced the osfteous tiss'iie which surrounded the silver ring, it was not conelusive, sitice, owing to the small .eircle of. periost,ynn reni<>ved, measuïirïg only- half anjnch.itVçiiainètcr* it~ïnight -he sald, bv way bf criticism, that thé periosteum, at either side might havegrown ijuickly Iv over the gap and then produced the osseous "f issue \\liich covered the silver .ring.- In order to meet this criticism two other experimei'fts were made. °
-J -l. -c- Fm; 2.– Silver ring exi>en- TWo inches of the diaphysis of the right radius, ̃ mCllt Xa o. !•• Specime" coinprising the wholë sh'aft with.the exception of half an _n,~nt Xo. 1. Spécimen p. thc wholë e s a, \V1 Lt Je exception ofhalfan ̃shows, the silver ring ex-t fi^m e;th hv8K|1 ];,“ wm. deniuleîï of periosteum shows thé removal ring ex-; ;f,therepiphvseanH.e,weredem~ofperiosteum poser! by removal of en- i-emovefl i i -i.ii.i- e • 1 vetoping portion ofl-one. which was eutirely removed along with thé superhc.al vetopiiig I)ortioii of I)one. •osseous laver of the shaft. Two silver rings were then placed upon thé centre of the. shaft about half an inch apart. During the necessary manipulation the connective tissue covering of one of the adjacent muscles was encroached on so as to expose- the mascular bundles, and thèse, naked muscular fascieufi came into direct contact with the denudeddiaphysis.
Aseptiç wound healing without visible cutanée scarresulted.
Description of Spccimen m si-en 7 treeks after ̃ (ÎR weeks and 6 days after). – There was no skin scar visible to the unaided eye. The periosteum at the epiphyseal ends ^was normal and could be separated from the undërlying bone readily. Toward the centre of the shaft, over the wholë extënt pfevtôusly denuded of periosteum, the soft