350 GASEOUS ANALYSIS OF MUSCLE. [BOOK I. 



employed in the analysis of muscle, but with much greater difficulty. 

 The difficulty is due in part to the nature of the method, for the 

 muscles cannot be transferred to the vacuum without preliminary 

 exposure to the contamination of air and indifferent fluids; and in 

 part to the nature of fresh muscle, whose tissue entangles bubbles 

 of gas, and whose gaseous contents, owing to the acidification of rigor 

 (p. 359), and to putrefaction, rapidly undergo change even at ordinary 

 temperatures. 



For the analysis of muscle a special boiling-flask is necessary, such 

 for example as is figured in the following diagram. 



A and B represent two views of the same apparatus, and the letters 

 are identical in their reference. 



v is the froth-chamber, a globe provided with a short neck g, fitting on 

 to the drying-chamber t but shut off from it by the stop-cock b. It is 

 provided also with a longer neck, h, at right angles to the other, interrupted 

 by a stop-cook c, and fitting into the boiling flask f. 



f is the boiling-flask, with a rounded bottom and a wide neck; it 

 is provided with three platinum wires melted through the sides and 

 reaching almost to the bottom of it. It is fitted on to the neck, h, of the 

 froth-chamber not quite at right-angles, as B shews, and in a plane at right- 

 angles to that of the neck g. f contains the muscle to be exhausted ; and at 

 the mouth of the neck h is a cork k grooved at the sides to permit the 

 passage of gases from f to v, while stopping any solid fragments which 

 might do damage to the stop-cock c. 



v serves a double purpose besides that of a froth-chamber : Firstly, any 

 liquid which spirts over from f during ebullition is collected here, and may, 

 by turning v round the axis of its neck g, be made to trickle back into f. 

 Secondly, a reagent, such as an acid, may be kept in v during the 

 preliminary exhaustion of a muscle in/, and by a similar tilting of v, may 

 be brought to play on the muscle at any given moment. 



t is a small drying chamber containing sulphuric acid, sufficiently large 

 to keep the vacuum of the pump dry so long as the stop-cocks c and b are 

 never open together ; by this means the access of watery vapour to the 

 absorption tube of the gas-analyser is prevented. The capacity of the 

 boiling-flask /, and the part of the neck h up to the stop-cock c, may 

 be about 200 c.cm. 1 



in Eozier's Observations sur la physique, Vol. xxxvii. 1790, p. 148. Muscle, cut into 

 small pieces, was enclosed in a glass retort connected with a pneumatic apparatus. A 

 very gentle heat was applied by means of a lamp for more than two hours, and the 

 gases which passed over into the pneumatic receiver were examined at different stages 

 of the experiment. At first atmospheric air passed over "mele* a une tres-petite 

 quantity d'air vital, dont le gaz nitreux indiquoit la presence ; " the second portions were 

 vital air, "mele" a du gaz acid carbonique." Girtanner very innocently remarks: "On 

 peut retirer la mme quantit6 de ce gaz [vital air or oxygen] plusieurs fois de suite, en 

 exposant des substances animates alternativement a 1'air atmosphe'rique et a une 

 chaleur de 60 a 70 degr6s du thermometre de Kdaumur." He found the exact adjust- 

 ment of the temperature a matter of great difficulty: "Si Ton applique un degre" de 

 chaleur trop fort, on aura du gaz acide carbonique au lieu de gaz oxigene." The 

 fallacies of the method lie on the surface, but do not destroy the historical interest of 

 the experiment. Girtanner further found that he could extract almost all the oxygen 

 which animal substances contain "par le moyen de 1'eau chaude. " 



1 Hermann, Untersuchungenu* d. Stojfwechsel der Muskeln ausgehend vom Gaswechscl 

 denelben. Hirschwald, Berlin, 1867, p. 4. 



