142 



III the first place it, became evident that though the results varied 

 considerably — this is easily explained by the changing condition 

 of weight etc. of the organ and the varying conditions for the 

 difTnsion of oxygen — the figures in the first place give a very 

 definite idea about the gaseous exchange in the electrical organ. 

 The electrical organ appears to consume 6 — 18 ni.ni*. 0, per gram- 

 hour, a quantity which is of the order of the 0, consumption of 

 the peripheral nervous system (Thunbkrg) ') which consumes about 

 7,0 <5f tJ'G quantity that is used by the central iieivous system. 



In 1883 Wey;, tried to demonstrate some chemical changes in the 

 electrical organ after it had shown vigoi'ous activity. He found a 

 change in reaction (hydiogen-ion concentration) i.e. an increase in 

 acidity after activity. Moreover, he tried to estimate the production 

 of CO, by the organ. Weyl found that 17,5 gms. pioduced 4 mgms. 

 00, in two hours. After stimulation he found a decrease instead of 

 an increase. The alcohol-extracts of a stimulated organ and one 

 which had not been stimulated, did not show any differences. The 

 watei-y extract of the stimulated organ was larger. 1 myself have 

 tried in vain to demonstrate the change in reaction after stimulation. 

 I ha\'e tried to demonstrate two chemical substances in the electrical 

 organ i.e. xantliin-bases and glycogen. This seemed to me to be of 

 impoitance, because we know that the electrical organ must be 

 derived from muscles in which both substances occur abundantly. 



The xanthin-bases were determined according to the method of 

 BURIAN: 



100 gr. of the organ are boiled for 12 hours in 1 L. of 0,5 7o HjSO^. After 

 filtration the sulfuric acid is precipitated with Ba(0H)2 and the liquid which is 

 now alcaline is filtered. The filtrate is saturated with GO.2. The BaGO is removed 

 by filtering and the filtrate, after acidification with acetic acid, is evaporated down 

 to 100 c.c. These 100 c.c. are boiled for some time with a smaller quantity of 

 concentrated NaOH + NagCO^ and filtered. The filtrate is acidified with HCl A 

 precipitate of xanthin bases now comes out on addition of an excess of NH3 + AgNOs. 

 In this precipitate nitrogen can be determined according to Kjehldahl. 



The following table gives the results of this investigation : (See 

 Table 2, following page). 



We may therefore conclude that the electrical organ contains no 

 xanthin-bases or a neglegible quantity. 



Determinations of glycogen were made in two very large animals 

 and 'n\ two young ones. 



^) Thunbeeg. Zbl. Physiol. 28 (1904). See also Buitendijk. Kon. Ak. v. Wetensch. 

 1910 (615—621). 



