° 1918 ] Lloyd, Extraction of Fat from Bird-Skins. 167 



the bottom flask in water or in ice water. The ventilation of the 

 room should be good, as the inhaling of ether produces headache 

 and, finally, anesthesia. Remove the specimen and place it on 

 clean absorbent cotton. Dry with a gentle blast of clean air, or 

 in a current of clean air. The feathers can be adjusted during 

 drying. Any dirt which had adhered to the fat will blow away as 

 dust. Cornmeal, used as ari absorbent in the preparation of skins 

 which were later cleaned by this method, fell out of the plumage 

 like sand, or was carried off by the air blast. 



This apparatus can be made of copper, if a large number of skins 

 are to be cleaned, and it can then be of considerable size and the 

 extraction chamber packed with specimens. If made of copper, 

 the top of the extraction chamber and condenser should be remov- 

 able. The joint where the cover with condenser attached joins 

 the extraction chamber must be gas-tight. In the copper appa- 

 ratus there should be a pipe provided with a stop-cock connecting 

 the bottom of the extraction chamber with the distillation flask. 

 The stop-cock should be closed during the extracting, but can be 

 opened to drain the ether from the extraction chamber before the 

 chamber is opened. In using a metal apparatus, the length of 

 time required for complete extraction of the fat will have to be 

 judged by experience. In the glass apparatus, the color of the 

 solvent in the extraction chamber indicates when the extraction 

 is complete. 



All skins must be dry before being subjected to this process. 

 If it is necessary to relax a skin before extracting, dry it temporarily 

 in a shape to fit the extractor, extract it, relax after ether has 

 evaporated and set again. 



Newly made skins known to be greasy can be treated as soon as 

 dry. The ether does not relax the skin in the slightest degree. 

 Some arsenic may be washed from the skin by mechanical action, 

 but sufficient will be left to render the bird-skin safe from insect 

 attacks. 



The use of such other solvents as petroleum ether, gasoline and 

 carbon tetrachloride for extracting fat can be experimented with 

 to advantage, using this apparatus. 



The author has used this method on the following specimens, 

 with the result recorded. After treatment, the specimens were 



