466 ELECTRO-PHYSIOLOGY CHAP. 



mond) that the reaction differs in resting, and in excited as well as in 

 dead muscle. The acidity is in the latter case so striking that it is 

 easily demonstrated by less sensitive methods. In the electrical 

 organ (of Torpedo} it is quite otherwise, as proved by repeated 

 observations of many authors who have investigated this point. 

 Boll (5 a}, who, like du Bois-Reymond, tested the reaction with 

 litmus-paper, found it unmistakably alkaline in the non-excited 

 organ (Torpedo}, and all later investigators have agreed with him 

 (cf. Th. Weyl, 36 &; W. Marcuse, 20). As regards post-mortem 

 acidity there is not, however, the same consensus of opinion. 

 While Boll and Weyl convinced themselves of its appearance, 

 Marcuse emphatically denied it. M. Schultze, again, found that 

 the electrical organ of freshly-killed torpedoes was constantly 

 very acid, which from analogy with the muscle was referred both 

 by Fuuke and du Bois-Reymond to an exhaustive effort of the 

 muscle previous to death, resulting from its frequent discharges. 

 Experimental results are, again, in direct contradiction with this 

 statement, neither strychnine poisoning, nor direct stimulation of 

 the electrical lobe, nor cutting-off the blood-supply being successful 

 in producing any marked degree of fatigue. Boll found none ; 

 Marcuse, who determined the reaction of the alcohol extract by 

 titration, with litmus-paper, detected only the merest shade of 

 difference between excited and non-excited organ (isolated by 

 section of the nerve), the second state being slightly more acid 

 than the first. 



Rohmann (29), who has recently repeated these investigations 

 at the zoological station at Naples, employed a method first 

 invented by Dreser (Cbl. f. Physiol. i. 1887, p. 195) for muscle. 

 This is based on the property possessed by acid-fuchsin, of 

 forming with the alkali of the tissue fluids a colourless combina- 

 tion, which breaks up again with quite weak acids (even CO.,), 

 and assumes a reddish colour. " If, after ligaturing the circula- 

 tion (in a frog), the sciatic nerve on one side is tetanised 

 intermittently (after previous injection of acid - fuchsin), there 

 will (in 1015 minutes) be a pronounced reddening of the 

 excited limb, which on the ground of the chemical properties of 

 the acid-fuchsin is a proof of the production of acid by active 

 muscle " (Dreser). Rohmami was able to establish a similar 

 reaction in the electrical organ, since in a torpedo injected with 

 fuchsin, and strychninised, or persistently excited from the lobe, 



