ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 877 



taining bottle ; Hoyer uses choral-hydrate (1 per cent, or more) for 

 the same purpose.* 



4. Acetic Acid Carmine.^ — Pulverized carmine added to a small 

 quantity of boiling acetic acid (45 per cent.) until no more will dissolve; 

 filtered and diluted to about 1 per cent, for use. 



Flemming used the concentrated solution. 



5. Grenadier's Carmine Solutions.^ — (i.) Alum Carmine. — An 

 aqueous solution of alum (1-5 per cent., or any degree of concentra- 

 tion) boiled with £-1 per cent, powdered carmine for 10-20 minutes; 

 allowed to cool, then filtered. 



With the addition of a little carbolic acid the fluid will keep for 

 years. It colours quickly, and nuclei more strongly than other parts. 

 Objects washed in water after staining. 



(ii.) Acid Borax Carmine. — a. An aqueous solution of borax (1-2 

 per cent.) and carmine (-g— f per cent.) heated till the carmine is 

 dissolved. 



b. Acetic acid added by drops to solution a, while shaking, until 

 the colour is about the same as that of Beale's carmine. 



c. Solution b left standing twenty-four hours, then turned off and 

 filtered. 



This solution, which is a modification of Schweigger-Seidel's acid 

 carmine, is not recommended for colouring in toto. It colours sections 

 in |— 3 minutes diffusely, and hence, after washing in water, they are 

 placed for a few minutes in alcohol (50 or 70 per cent.) to which a 

 drop of hydrochloric acid has been added ; then transferred to pure 

 alcohol. 



(iii.) Borax Carmine.§ — a. An aqueous solution of borax (4 per 

 cent.) and carmine, heated till the carmine is dissolved. 



6. Solution a mixed with 70 per cent, alcohol in equal parts, left 

 standing twenty-four hours and filtered. 



This fluid may be used for colouring objects in toto. After stain- 

 ing, the objects are to be washed in 35 per cent, alcohol, to which a 

 little hydrochloric acid has been added (4-6 drops to 100 ccm.), and 

 allowed to remain here until the colour has been sufficiently removed. 

 They are next passed through successively higher grades of alcohol 

 for hardening. 



(iv.) Alcohol Carmine. — A teaspoonful of carmine dissolved, by 

 heating about ten minutes, in 50 ccm. of 60-80 per cent, alcohol, to 

 which 3-4 drops of hydrochloric acid have been added, then filtered. 



* Dr. Lang's picro-carmine and eosin method for Planarians, see this Journal, 

 ii. (1879) p. 163, is also referred to. Dr. Mayer does not expect any particular 

 advantage from its application to Arthropods. 



t Schneider, Zool. Anzeig., 1880, p. 254. 



X Grenacher, " Einige Notizen z. Tinctionstechnik," Arch. f. Mikr. Anat, 

 xvi. (1879) p. 463. None of these solutions should be used where calcareous 

 parts are to be preserved. 



§ Dr. Mayer prepares, for some purposes, borax carmine of 50, 60, or 70 per 

 cent. That of 70 per cent, contains little carmine, but is well adapted to staining 

 delicate objects that would suffer if exposed to weaker solutions. Boiling alcohol 

 (50 per cent, or 60 per cent.) dissolves about 1 per cent carmine and 1 per cent, 

 borax. 



Ser. 2.— Vol. II. 3 N 



