PROFESSOR THOMSON ON DISTORTED HUMAN SKULLS. 403 



do not differ much in chemical composition from recent bone. The 

 inori^anic matter (73.243)* is apparently greatly in excess, but its 

 proportion is increased by a considerable quantity of fine silicious 

 sand, which has sifted into the cancelli. Allowing for this infiltrate, 

 we may regard the amount of organic matter (26.757) as little below 

 the average. It is most likely that all the constituents of a given 

 portion of bone have been slowly and pretty equally reduced. 



The relative amount of organic matter in these bones from the 

 Orchard ; in a bone of the short-horned ox, in the ordinary state of 

 preservation from the marl at the bottom of an Irish bog (Postpleis- 

 tocene) (37.221) ; in a bone of the same species, domesticated by the 

 Eomans (a.d. 300) at Uriconium (20.172) ; in the bone of an Irish 

 elk (Postpleistocene) (37,2) — seems clearly to show the extremely 

 limited value of a theory such as that of M. Couerbe (quoted in the 

 Lancet, Feb. 22nd, 1862), that bones lose 3 per cent, of organic matter 

 in a century. Possibly such a generalization may apply to bonfes 

 slowly decaying in dry air in a stone coffin, but in the case of buried 

 bones the proportion of their organic to their inorganic constituents, 

 at the end of a hundred or at the end of ten thousand years, would 

 depend entirely upon the circumstances of their burial. 



In this discussion I have purposely omitted the possible case of 

 bones being first distorted and then fossilized. This double change 

 occurs in some mammalian remains from the French tertiaries, but 

 no cases have as yet been met with which bring it within the scope 

 of the present inquiry. 



The question as to the cause of the constancy in the style of 

 deformity is one of rather greater difficulty. As I have stated above, 

 the skulls presenting this peculiar distortion have all, so far as I am 

 aware, been found surrounded, supported, and filled with vegetable 

 mould. Some of them — for example, those from the Orchard at 

 Uriconium — had undoubtedly been buiied at once in the soil without 

 any coffin or external defence, and it is very probable that all may 

 have been interred either in this most simple way or in rude stone 

 chambers, which were either filled up with earth at the time of 

 burial, or into which the soil shortly afterwards drifted. We may 

 then conclude that in all, before the body was thoroughly decom- 

 posed, the head was supported in the position which it had assumed 

 at the time of burial. 



A glance at the position of the heads on the slate slabs of a 

 dissecting-room will show at once, not only that it is a matter of some 

 delicacy to poise and support the head vertically on the apex of the 

 occipital protuberance, on a plane surface, a delicacy which our 

 ancestors were little likely to attend to in their ruder forms of burial, 

 but that the heads tend to fall over to either side, and to remain 



* For careful and valuable analyses of these and other bones, fossil and sub- 

 fossil, I am indebted to my friend Dr. McCrea, chemical assistant in Queen's College, 

 Belfast. As Dr. McCrea means to continue his researches, I shall leave the details 

 of his results to be given by himself in a future paper. 



