Intelligence and Miscellaneous Articles. 545 



when putrefaction is set up. There is only a single case in which 

 muscular fibre, still endowed with all its vital properties, presents an 

 acid reaction, namely when it has just passed through a phase of 

 prolonged activity. 



As early as 1842, M. du Bois-Reymond ascertained that an arti- 

 ficial transverse section of perfectly fresh muscles did not redden 

 litmus-paper ; however, as he was previously convinced from other 

 researches that the electro-chemical antagonism of the transverse 

 and longitudinal sections cannot be the cause of the muscular cur- 

 rent, and as he did not dream of suspecting the accuracy of the 

 observations of chemists, he assumed that the supposed acid liquid 

 of the transverse section had been neutralized by the alkaline liquid 

 issuing from the blood-vessels and lymphatic ducts. Subsequently 

 M. du Bois-Reymond had the opportunity of observing that the 

 artificial transverse section of the muscle of a frog has a chemical 

 action, in course of time, upon the substance of another muscle, and 

 consequently acts upon it as a destructive agent of the parelectro- 

 nomic layer. It is a remarkable fact that the longitudinal, artificial 

 or natural section of muscle is incapable of acting in this manner. 

 The muscular fibres must therefore contain a liquid capable of acting 

 upon the contents of those fibres, which is a contradiction, or a 

 liquid capable of attacking the fibres is formed, in course of time, at 

 the surface of transverse artificial sections. Experiment soon de- 

 monstrated the correctness of the latter supposition. In fact, the more 

 recent the transverse section, the less intense is the corrosive action. 

 This action was found to result from the formation of an acid. 



From his numerous experiments upon animal electricity, M. du 

 Bois-Reymond knew that the superficial layer of the transverse sec- 

 tion loses its vital properties very rapidly. Thus he was very natu- 

 rally led to think that the acid is only set at liberty in the muscular 

 substance after the death of the latter. A long series of experiments 

 proved that this supposition was perfectly correct. When the trans- 

 verse section of a muscle has become acid, a new section with a neu- 

 tral reaction may be obtained by the removal of the superficial layer. 

 When this new section becomes acid in its turn, a new neutral sec- 

 tion may be obtained by its removal, and so on. It is only from the 

 moment when the rigor mortis is set up, and all the vital properties 

 are extinct, that all the transverse sections of the muscles present an 

 acid reaction. The longitudinal sections, however, still give an 

 alkaline reaction. Subsequently the alkalies which were contained 

 in the muscle are entirely neutralized by the acid, and every point 

 of the muscular mass reddens litmus-paper. By degrees putrefac- 

 tion comes on, but the result of this putrefaction is the formation 

 of carbonate of ammonia, so that soon the acid jeaction disappears, 

 and gives place to an alkaline reaction. It is therefore evident that 

 the acidity of the muscles, which has occupied so much of the atten- 

 tion of chemists, i.ily dates from the moment of the establishment 

 of the rigor mortis. 



It may be thought that the muscular acidity is the result of an 

 oxidation. M. du Bois-Reymond shows that in every case there is 

 Phil. Mag. S. 4. No. 123. Sujrpl. Vol. 18. 3'N 



