APPENDIX TO THE HISTOLOGICAL SECTION. 117 



Carmine gelatin mass. Take 4* of carmine and dissolve it in the 

 least quantity of strong ammonia in a mortar, let it nearly dry up, 

 much superfluous ammonia is thus got rid of, and rub it in 50 cc of 

 distilled water. When completely dissolved filter and warm. Place 

 10& of clear gelatin cut up small into 50 cc of distilled water. When 

 the gelatin is completely swollen up heat it in the water-bath until it 

 is dissolved. Add the gelatin to the carmine with constant stirring until 

 incorporated, and then add drop by drop a 10 P- C - solution of acetic acid until 

 the colour of the whole is changed to a brighter red, the transition 

 is a very noticeable one ; the mixture should have a distinct odour 

 of acetic acid and have an acid reaction. The carmine is thrown 

 out of solution, but no precipitate should be visible under the highest 

 power. Strain through flannel which has been wrung out of hot water. 



