480 APPENDIX III. 



grammes neutral acetate of ammonia, and O'l gramme calcium 

 chloride, dissolved in 200 c.c. distilled water. 



Copper Acetate. Is a reagent for Tannin. For use, see p. 71. 

 Ammon-oxide (cuprammonia, ammoniacal cupric oxide, also known 

 as Schweizer's Reagent). Oxyhydrate of copper is carefully precipi- 

 tated from a solution of the sulphate by a dilute solution of ammonia 

 or of caustic soda ; the clear green precipitate, separated and 

 repeatedly washed with water, is added while still moist to strong 

 ammonia, in which, upon slightly warming, it is dissolved. Upon 

 cooling, crystals of sub-sulphate of copper and ammonia fall to the 

 bottom. The filtered liquid contains only the ammoniacal cupric 

 oxide in solution. It must be kept in bottles of dark glass, or in 

 the dark. It can also be prepared by digesting copper turnings in 

 an open bottle with the liquor ammon. of the Pharmacopoeia. As 

 it is very easily decomposed by light, it is perhaps best prepared 

 fresh, when required. It is a reagent for cellulose, which it dis- 

 solves after great swelling. The early stages of swelling often bring 

 out structure with great beauty. It is fit for use only so long as it 

 rapidly dissolves cotton-wool. 

 Sulphate. Used in Fehling's solution for sugar, 66. 



Gorallin solution. Dissolved in a 4 per cent, aqueous solution of carbonate 

 of soda. To prevent its altering, a little camphor can be added to 

 the solution. Constantly used for staining and differentiating 

 mixed tissues. Specially stains lignin, sieve-callus and starch. 

 .According to Zimmermann, the callus reaction comes out best with 

 overstating and washing the surplus corallin out with 4 per cent, 

 soda, and that it is especially good with fungi. The colour is not 

 permanent. 



Corrosive sublimate. Often used for fixing purposes. Can be removed from 

 the preparation or fixed material by a solution of iodine. 



Creosote. A good clearing reagent, but inferior to chloral hydrate for grow- 

 ing points, etc. It works very well after dehydration, as preparatory 

 to mounting in Canada balsam. 



Crystal Palace glass cement, or other similar cement, such as Coaguline. For 

 fixing card labels on object-slides. 



D. 



Dammar, Gum. Dissolved in warm turpentine, and evaporated to the 

 thickness of syrup. Can be obtained in tubes ready for use. It is 

 a useful mountant for bacteria and filamentous algae, after dehydrat- 

 ing and clearing, p. 302. 



Diastatic ferment. Prepared as shown on p. 23 for the corrosion and solu- 

 tion of starch-grains. 



Diphenylamine. 0*05 gramme in 10 c.c. pure sulphuric acid. Used as 

 reagent for nitrates and nitrites. See p. 67. 



