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SCIENCE- G OS SIP. 



CLEANING SKULLS AND SKELETONS. 



By Lionel E. Adams, B.A. 



"1 TAVING lately noticed several queries in 

 J — ■- various papers as to the best metliod of pre- 

 paring skulls and skeletons, I have thought that 

 the results of an experience of this work during 

 the last thirty years may be of interest to the 

 readers of Science-Gossip. 



The Ant-hill Method. 

 Of course everyone has heard of the ant-hill 

 method of cleaning bones, but those who have 

 tried it, at least in this country, are not likely to 

 repeat the experiment. The flesh is certainly 

 cleared away more or less completely, but the soil 

 and damp discolom- and rot the bone, and it 

 takes some months for the ants to deal with even 

 so small an object as the skull of a mouse. In 

 tropical regions the ants may do their work more 

 expeditiously ; but my own experience has not 

 been satisfactory with the only specimen I tried — 

 viz. a vulture's head. This I suspended on a wall 

 in the swarming track of some red ants, and, 

 though most industrious, they failed to make much 

 impression on it in three weeks. 



By Tadpoles. 



I once found a minnow in my aquarium reduced 

 to a fairly complete skeleton by tadpoles ; but 

 these little creatures cannot manage any tough 

 integument. 



By Shrimps. 



Judging from skeletons which have lain in the 

 sea water where shrimps abound, I should say they 

 were the most capable of all such small scavengers. 

 I remember a case some few years ago of the body 

 of a man recovered three or four days after he had 

 been drowned in the sea. The body was found 

 perfectly skeletonised, and his clothes, by which 

 alone he was identified, were full of shrimps. 



Sand, Sea Water, Sun, and Wind. 

 Dr. R. J. Scharff, of the Dublin Museum, once 

 informed me that he was very successful with the 

 skeleton of a whale, which he buried in the sand 

 within reach of the tide. No doubt in this case 

 maceration and small crustaceans were mutually 

 useful. That there is great bleaching virtue in sea 

 water, especially if assisted by sun and wind, any- 

 one will acknowledge who has found bones on the 

 sea-shore. I have no doubt that the white con- 

 dition of the bones piled up in Hythe Church 

 crypt in Kent is due to the bodies having been 

 left, perhaps buried, on the sea-shore, which was 

 the scene of the battlefields, till the sea and small 

 crustaceans had purified them. These bones have 



certainly not been buried in inland soil, or they 

 would have lost their surface polish, have become 

 discoloured, and lost more of their weight. A very 

 similar collection of bones in the crypt of Roth- 

 well Church, Northants, is in a very different con- 

 dition, the bones shovdng all the signs of having 

 been buried in the ironstone soil of the district. 



Even sand alone under some conditions is favour- 

 able to bleaching. Scattered over the desert are 

 commonly found beautifully perfect specimens of 

 camels' and jackals' bones, which have been cleaned 

 first by the vultures and flies, and then by the hot 

 sand blown along by the wind. At Suez in 1872 

 I used to visit an old cemetery where victims of a 

 former plague had been interred in the desert sand. 

 Here I found all the bones in a remarkable state of 

 preservation, and, though the short black hairs of 

 shaven crowns were still to be found on many of the 

 skulls, all the bones were beautifully white and 

 glossy. They were then being dug ujj and utilised 

 for making lime for building purposes. 



The Boiling Method. 



Another rough-and-ready method is to boil, or 

 rather simmer, the skull for some hours until the 

 flesh is quite gone ; but specimens so treated are 

 always more or less discoloured. We all know the 

 dirty gi'ey appearance of boiled bones. This dis- 

 coloration, however, may be lessened if the water 

 is not allowed to i-each the boiling-point, and if it 

 be changed from time to time as it becomes dirty. 

 A little washing soda may be added at the last 

 stage of simmering, or a small quantity of Hudson's 

 dry soap, or ammonia, which eliminates the grease. 

 For large skulls where delay is impossible this 

 method is perhaps the best ; but for small delicate 

 skulls, like those of the bats and shrews, nothing but 

 water should be used, or the bones will part at the 

 sutures. 



By Maceration. 



The best results, however, are obtained in the 

 following manner : — Remove all the flesh and 

 detach the lower jaw. Scoop out the brain through 

 the foramen magnum and place the skull in hard 

 water. Rain water should be carefully avoided, 

 as it often turns the skulls green or black. The 

 water should be changed daily, and the skull as 

 constantly picked, until little by little it becomes 

 free from everything that the scalpel or scissors 

 can remove. 



During the process of maceration the remaining 

 portions of the brain and dura mater can be got 

 rid of by an injection of water with a squirt. 



