[21] COLLECTING ANTHEOPOLOGICAL INFORMATION HEDLICKA. 



gencies is patient manipulation or careful repair by fitting- of the 

 separated parts and additions of plaster to the outside of the cast. 



The orbits and nostrils in the finished cast are filled with plaster and 

 the whole is allowed to dry, after which, if the cast is to shipped, it 

 must be prepared for the positive. This is done b}^ simply soaking 

 the cast in a strong solution of common soda (sodium carbonate); or 

 by the soaking and subsequent careful application of thin oil to the 

 inner surface. These processes, with the staining of the negative 

 cast, facilitate its subsequent chipping off from the positive. » 



The last step consists in carefully mixing a larger quantity of plaster, 

 with addition of salt but not of coloring matter. Pour some of this 

 into the negative, and bj^^ inclining the latter in all directions allow the 

 plaster to form a good, thin covering of the whole inner surface. 

 Then gradually add more plaster, persisting in the slow movements, 

 and finalh' help with the spatula or spoon. It is desirable to make 

 the positive at least half an inch thick. Mark then on the concave 

 surface of the positive with some sharp point whatever data are essen- 

 tial to go with the casts, and allow the whole to dry thoroughly before 

 packing. 



In the manner just described, with a little preliminary practice and 

 continual care, from eight to ten first-class facial casts can be made in 

 a day. Different operators ma}^ use methods that vary more or less 

 from the above, and there is no harm in adopting any modification 

 that tends to facilitate the procedure or improve the result. Some 

 operators try to secure a cast of the whole head, but this has no 

 advantage. With a good facial cast and photographs the head can be 

 modeled almost to perfection. 



Casts of the body should never be undertaken except by one well 

 practiced in the art, for the operation is not without danger to the 

 subject. 



Casts of the lowest part of the trunk and of the limbs can be made 

 without any very great danger or difficulties, but they also need 

 experienced hands. 



The skin must in all instances be well oiled and the part must not 

 be deformed by wrong position or pressure. A provision for the 

 removal of the cast in sections must also be made, which is usually 

 done by including in the first lajxr of plaster, along the line of 

 intended separation, a linen thread, and by cutting the cast with this 

 as it begins to harden. The preparation of the plaster and other 

 details are practically the same as in facial casting. 



In packing casts, pad well and tightly with very dr}'^ ha}^ or other 

 suitable substance, and use only small boxes or barrels. 



