396 PROF. TH. W. ENGELMANN. 



the normal movement is often observed to be accelerated.^ In 

 diluted acids death generally sets in with opacity and shrink- 

 ing (coagulation of the albumen).^ Carbonic acid has also 

 this result, if passed over the preparations in a concentrated 

 stream for some time.^ Movements, which have stopped in 

 consequence of the action of weak CO2 can by its replacement 

 by air, generally also by hydrogen, be reinduced, in conse- 

 quence of which any existing opacity is removed. 



Ether or chloroform act in the same way as CO2 causing a 

 temporary or permanent coagulation. They need only be 

 mixed in small quantities with the air to effect their destruc- 

 tive action, which is also at first easily stayed by the introduc- 

 tion of pure air.* 



It is interesting to note, as they specially agree in this respect 

 with the contractile substance of muscle fibres, that many kinds 

 of protoplasm are acted on in a poisonous way by veratrin.^ 

 Kiihne observed that freshwater Amoebae,^ Actinosphae- 

 rium,'' and Myxomycetes,^ in exceptionally diluted, barely 

 alkaline, even neutral solutions of this poison, become quickly 

 coagulated, becoming opaque and completely breaking up. Tra- 

 descantia cells, however, still showed the normal movements 

 after seventeen hours' immersion in a watery veratrin solution. 



Binz^ and others have observed that quinine exercises a 

 strongly destructive action on many kinds of protoplasm and 

 on colourless blood-corpuscles. On the other hand, I have 

 given frogs such large doses of quinine sulphate by subcuta- 



1 By Dutrochet (I.e., p. 781), in Chara; By Kiihne (I.e., p. 49), in 

 Amceba. 



2 Kiihne, 1. c., pp. 49, 64. 



* Ibid., p. 51 (Amoeba); p. 67 (Actinosphserium); p. 90 (Myxo- 

 mycetes) ; p. 106 (Tradeseantia). 



'' Ibid., p, 66 (Actinosphaerium) ; p. 100 (Tradeseantia). 



* Kiihne, 1. c., p. 47, et seq. 

 ^ Kiihne, 1. c., p. 47. 



7 Ibid., p. 65. 

 ^ Ibid., p. 86, et seq. 



' C. Binz, " Ueber die Einwirkung des Chinin auf Protoplasma-bewegung," 

 'Arch. f. Mikr. Anat.,' iii, p. 383, 1867. 



