USE OF THE SUTURES. 54'5 



the barrel, and another in the muffle ; they agreed in indi-~" 

 eating 23^. The inner tube, which was of Reaumur's porce- 

 lain, contained eighty grains of pounded chalk. The carbo- 

 nate was found, after the experiment, to have loft 3f grain-;. 

 A thin rim, lefs than the 20Lh of an inch in thiclcnefs, of 

 whitidi matter, appeared on the otUfide of the mafs. In other 

 refpedts, the carbonate was in a very perfe6t ftate ; it was of a 

 yeI!owi(h colour, and had a decided femitranfparency and 

 faline fradure. But what renders this refult of the greateft 

 value, is, that on breaking the mafs, a fpace of mi^re than the 

 tenth of an inch fqnare, was found to be completely cryftal- 

 lized, having acquired the rhoraboidal frafture of calcareous 

 fpar. It was white and opaque, and prefented to the view- 

 three fets of parallel plates which are feen under three different 

 angles. This fubflance, owing to partial calcination and fub- 

 fequent abforption of moifture, had loft all appearance of its 

 remarkable properties in forae weeks after its produdlion ; but 

 this appearance has fince been reftored, by a frePn frafture, 

 and the fpecimen is now well preferved by being hermetically 

 inclofed, 



(To be continued.) 



XIIL 



On the Ufe of the Sutures in the Skulls of Animals. By 

 Mr. B. Gibson *. 



JL HE full ufe of the fingular jun6lion of the bones of the Conj^fturesoa 

 Ikull, which is called future, has, from the earlieft periods "' futures b [he 

 anatomy and forgery, attraded the attention and eluded the ikulls of aninuls. 

 refearches of the phyfiologift. To this remarkable feature in 

 ofteogny, in a great meafure peculiar to a certain period of 

 life, many ufes have been attributed. Some of thefe are 

 totally erroneous ; fuch as that for allowing the tranfpiration 

 of moifture, to keep the brain cool and fit for thinking ; for 

 giving a more ftridt adhefion of the dura mater to the inner 

 furface of the flcuU ; for admitting a more free communication 

 by blood-veflels between the external and internal parts of the 

 head; or for affording interftices, that the bones may be 



« Manchefter Memoirs, N. S. Vol. I. 39. 



B b 2 puOved 



