NERVOUS SYSTEM 



51 



TABLE 35 Concluded. 



In a later study King ('13 a) followed in some detail the ef- 

 fects of formaldehyde on the brain of the Albino. The conclu- 

 sions reached were as follows: 



1. A 4 per cent solution of formaldehyde causes a pronounced swell- 

 ing in the brains of rats of all ages. 



2. A solution of formaldehyde undergoes some chemical change on 

 standing, since a solution five months old causes less swelling in the 

 brain of the rat than does a freshly made solution. 



3. A 4 per cent solution of formaldehyde neutralized with NaCOs 

 produces a much greater amount of swelling in the brain of the rat 

 than does a solution that has a faintly acid reaction. 



4. A strong neutralized solution of formaldehyde causes a greater 

 percentage weight increase in the rat's brain than does a weak neutral- 

 ized solution. A reverse result is obtained when the solutions are not 

 neutralized. 



