[19] COLLECTING ANTHEOPOLOGICAL INFORMATION HRDLICKA. 



It is more valuable to send negatives with prints, than prints alone; 

 in a laboratory almost all negatives can be more or less improved, 

 while the possible bettering- of the prints is very limited. It is also 

 nmcli easier to make a good lantern slide or enlargement from a nega- 

 tive than from a print. 



In rapid or extensive traveling it may be impracticable to use glass 

 plates and recourse must be had to films. These do not often make as 

 valuable negatives as the glass plates, yet if the camera and the proc- 

 ess of photography are well understood the results may be very service- 

 able. 



With each photograph or negative of an individual should be sent 

 data as to the tribe or nationalit}^, place of birth, name, sex, age, and 

 tribe or nationality of father and mother. An identification mark 

 should be scratched in a corner on the negative itself. 



Facial or head casts are made from plaster of Paris. Efliciency in 

 making casts is best acquired under an instructor. To the proper per- 

 son an opportunity to learn the procedure will be provided at the 

 National Museum, 



The process of making a facial cast, given here for those who have 

 a chance to practice it, is as follows: 



Have the subject comfortably seated on a chair with a back and head 

 rest. See that the face preserves throughout its most natural expres- 

 sion, the eyes being open, and warn the subject against moving, 

 swallowing, coughing, sneezing, or spitting. The lips should not be 

 held tight or puckered, or the mouth distorted. Fasten a wide, ample 

 piece of muslin, like an apron, below the neck of the subject. Brush 

 the hair -backward, without pulling the skin, and fasten it by a moder- 

 ately tightly applied muslin band about 2i inches broad, leaving all 

 around the forehead and temples a little of the hair exposed. 



Work into this visible portion of the hair, and also into the eye- 

 brows, mustache, and beard enough soap paste to prevent inclusion 

 into the plaster. Use either the commercial green soap that comes in 

 paste, or boil ordinary soap with water until the liquid thickens. 

 Introduce a little cotton into each ear. Oil, by means of a camel's-hair 

 brush, the whole face and neck with light paraffin oil (or any other 

 oil that is not viscid); also oil the hair band. Care must be exercised 

 that no excess of the oil is left anywhere and that nothing enters the 

 eye. This finishes the preparation. No nasal tubes are required. 



The next step consists in mixing the plaster. Only the best dental- 

 plaster should be used. Fill a small basin, of any kind, with luke- 

 warm, or at least not too cold, water, add a pinch of common salt and 

 some wash blue or other coloring matter. Sift the plaster onto the 

 top of the water from your hand, without mixing, until the moment 

 when it stops sinking — this exact stage must be learned from practice. 

 Mix then, without churning, with a common spoon, gather the sur- 



