177 



If the experiments referred to be made with quantities of chloro- 

 form sufficiently large to touch the walls of the containing vessel on 

 every side, and to form a stratum of some depth, the effect of adding 

 alkaline water is to give the chloroform a surface apparently hori- 

 zontal, and the addition of acids makes its upper boundary highly 

 convex. 



Change in configuration, however, is not the only alteration which 

 the globule of chloroform undergoes. Several of its physical pro- 

 perties are strikingly modified by its contact with aqueous solutions 

 of acids and alkalies. When these are alternately made to act on 

 chloroform at the bottom of a flat white porcelain vessel, which 

 admits of the resulting phenomena being distinctly observed, the re- 

 agents in question change the sensible characters of the denser liquids 

 in the following way. Under acidulated water the globules are bril- 

 liant, very mobile, and obedient to the solicitation of gravity. De- 

 tached globules, when they meet, readily run together, and scarcely 

 one is to be seen without a bubble of air attached to its upper sur- 

 face, and adhering tenaciously. Under alkaline water, on the other 

 hand, the globules of chloroform spread out into flat discs, with 

 rounded edges ; or elongated into irregularly ovoidal or flattened 

 cylindrical forms, which vary their shapes on the slightest impulse. 

 These flattened globules are, moreover, much less mobile than the 

 rounded ones under acid. They move sluggishly, cling to the vessel, 

 and leave a tail behind them when urged to move rapidly. Their 

 brilliancy is sensibly diminished, and no air-bells adhere to their 

 upper surfaces. 



Chloroform admits of being coloured by digestion on litmus, 

 alkanet root, &c. &c. Globules of the coloured liquid flatten out 

 greatly more under alkalies than the colourless chloroform does, so that 

 blue or red globules spread over an irregular area five or six times 

 greater than they occupy under acids. Their apparent viscidity, loss 

 of mobility and of brilliancy, are also more marked than when colour- 

 ing matter is absent. 



Phenomena similar to those noticed with the colourless chloroform 

 were observed with the several liquids previously mentioned. The 

 author, in conclusion, declined to enter on the theory of the pheno- 

 mena described, further than to ascribe an important share in their 

 production to the action of lighter and heavier liquids on each other. 



