278 PROCEEDINGS OF THE NATIONAL MUSEUM. 



thirty days. Other weighings, as indicated in the detail tables, were 

 taken thereafter. At the end of the seventh and the thirtieth day the 

 solution and cotton were changed, as is done with all specimens in the 

 museum collection. The drainage of each specimen was as uniform 

 as practicable by the method outlined in the first part of this paper. 

 The solutions employed were: 



1, Three per cent formalin. 



2. Five per cent formalin. 

 8. Ten per cent formalin. 



4. Fifteen per cent formalin. 



5. Saturated solution of common salt with 5 per cent formalin. 



6. 1,030 sp. gr. common salt solution with 5 per cent formalin. 



7. 1,015 sp. gr. common salt solution with 5 per cent formalin. 



8. Saturated solution of alum with 5 per cent formalin. 



9. One-third saturated solution of alum with 5 per cent formalin. 



10. One-fifth saturated solution of alum with 5 per cent formalin. 



11. One-third saturated solution of ahim with common salt up to sp. 

 gr. 1,030, with 10 per cent formalin. 



12. Saturated solution of alum with 5 per cent formalin. 



13. Eight}' parts of 1>5 per cent alcohol and 20 parts of 5 per cent 

 formalin. 



14. Sixt^'-five parts of 95 per cent alcohol and 35 parts of 3 per cent 

 formalin (near that of Parker & Floyd). 



15. Sodium acetate 130 grams, sodium chloride 110 grams, formalin 

 20 c. c.,95 per cent, alcohol 460 c. c, water 540 c. c. (Stroud, Wilder). 



The results, in detail, were as follows: 



THREE PER CENT FORMALIN. 



End of first week: The weight of brains in the 3 c. c. to the gram 

 solution had risen in average 21 per cent, or over one-fifth of the 

 original. Variation: From 118.55 per cent (specimen of 102 grams 

 original weight) to 123.9 per cent (specimen of 102.5 grams) = 5.37 

 per cent. The two heaviest brains (117.5 and 110.5 grams) gained, 

 resi)ectively, 20 uiid IS. 55 per cent in weight, the two lightest ones 

 (94 and 93.2 grams) 20.2 and 22.1 per cent. The brain in the 6 c. c. 

 to the gram solution (100.5 grams original weight) increased 18.9 

 per cent, less than any other except one of the heaviest specimens, 

 and the one weighed every day, which may have been affected thereby. 



End of first month: Weight of five of the nine brains in the 3 c. c. 

 to the gram solution is very slightly greater (+0.08 to +0.44 per 

 cent); of three, slightly smaller (-0.42 to -1.15 per cent), and of 

 one, equal. Variation: From 117.19 to 124.(12 per cent^'=^6.8 per cent. 

 The changes were not quite harmonious with those of the first week, 

 or proportionate to the weight of the specimens. The brain in the 6 



« As compared with oriyrinal weight. 



