1873.] Sir B. C. Brodie on the Synthesis of Marsh-gas, fyc. 245 



Various observers are then quoted in support of the accuracy of the 

 description given ; and the probability is pointed out, and supported by 

 an observation of Prof. Briicke, that in all cases in which alternating 

 disks of isotropous and anisotropous substances are observed, the 

 muscular fibre is in a state of contraction (although not necessarily 

 shortened) — that is to say that the anisotropous substance has become 

 accumulated between the shafts of the rods, the isotropous disks being 

 due to the rod-heads, between which there is no perceptible amount of 

 anisotropous substance left remaining. 



The author concludes the paper by offering a conjecture as to the 

 nature of the substances which, according to his description, compose 

 the proper substance of muscle, and as to the probable mode in which 

 the contraction is effected. He is inclined to regard the intermediate 

 ground-substance as the true contractile part, and thinks that it may be 

 allied in nature to ordinary protoplasm, the rods, on the other hand, 

 being elastic structures, and merely serving to restore the fibre to its 

 original length. 



II. " Note on the Synthesis of Marsh-gas and Formic Acid, and on 

 the Electric Decomposition of Carbonic Oxide/'' By Sir B. C. 

 Brodie, Bart., D.C.L., F.R.S., late Waynflete Professor of 

 Chemistry in the University of Oxford. Received April 3*, 

 1873. 



In connexion with the investigation on the electric decomposition of 

 carbonic-acid gas referred to in a previous communication to the Society, 

 I was led to submit a mixture of hydrogen and carbonic-oxide gas to the 

 action of electricity in the induction-tube, the mixed gases being circu- 

 lated through the tube by means of an apparatus which I will not now 

 describe. A contraction was soon observed to have taken place, which at 

 the end of an hour amounted to 10 cub. centims. The rate of contrac- 

 tion steadily diminished, and during the fifth hour of the duration of the 

 experiment amounted to only 2 cub. centims. The experiment was 

 stopped, and the gas analyzed with the following results in two several 

 analvses : — 



I. 



Carbonic oxide 61*65 



Hydrogen 32-16 



Marsh-gas. . 6*14 



100-00 



n. 



Carbonic oxide 61-35 



Hydrogen 32-34 



Marsh-gas 6-31 



100-00 



A small quantity (about 2 per cent.) of nitrogen was also contained in 

 * Received in nearly the same form March 27. 



