463 Prof. Matteucci's Experiments in Electro-physiology. 



that the oxygen which furnishes the carbonic acid exists in the 

 muscle in a state of combination. According to the theories of 

 Joule, Thomson, &c., the chemical action which is transformed, 

 or which gives rise to heat, is also represented by a certain quan- 

 tity of vis viva, or by an equivalent of mechanical work. I have 

 therefore been able to measure the theoretical ivork due to the 

 oxygen consumed, taking the numbers which I had foiind for 

 muscular respiration during contraction, and in consequence the 

 quantity of heat developed by this chemical action, and finally 

 this theoretical work according to the dynamical equivalent of 

 heat. I have compared this number with that which expresses 

 the real tvork which is obtained by measuring the weight which 

 a muscle in contraction can raise to a certain height, and the 

 number of contractions which a muscle can perform in a given 

 time. It results from this comparison, that the first number is 

 somewhat greater than the second, and the heat developed by 

 contraction ought to be admitted among the causes of this slight 

 difference : these two numbers are therefore sufficiently in ac- 

 cordance with each other. 



I completed these researches by some new studies on induced 

 contraction, that is to say, on the phsenomenon of the irritation 

 of a nerve in contact with a muscle in contraction. A great 

 number of experiments lately made on the discharge of the tor- 

 pedo, and on the analogy between this discharge and muscular 

 contraction, have led me to establish the existence of an electrical 

 discharge in the act of muscular contraction. The general con- 

 clusion to be drawn from these researches is, therefore, that the 

 chemical action which accompanies muscular contraction devc- 

 lopes in living bodies, as in the pile or in a steam-engine, heat, 

 electricity, and vis viva, according to the same mechanical laws. 



Allow me to describe to you briefly the only one of these ex- 

 periments which can be repeated in a lecture, and which proves 

 the principal fact of these researches, although it is limited to 

 prove that muscles in contraction develope a greater quantity of 

 carbonic acid than those in repose. Take two wide-mouthed 

 glass phials of equal size, 100 or 120 cub. centims. ; pour 10 

 cub. centims. of lime-water (eau de chaux) into each of these 

 phials. Prepare ten frogs in the manner of Galvani, that is, 

 reducing them to a piece of spinal marrow, thighs and legs 

 without the claws, which are cut in order to avoid contact with 

 the liquid in the pliials. The cork of one of these phials is pro- 

 vided with five hooks, either of copper or iron, on which five of 

 the prepared frogs are fixed. Through the cork of the other 

 phial are passed two iron wires, bent horizontally in the interior 

 of the phial ; the other five frogs are fixed by the spinal marrow 

 to these wires. This preparation must be accomplished as rapidly 



