On Intestinal Rest and Movement. 



215 



was employed. This constituted the " sound," and was connected 

 by means of a system of thick- walled india-rubber tubes with a 

 mercurial manometer or a Marey's recipient tambour ; if the former 

 was employed water was the means of communicating the impulse 

 from the compressed sound ; if the latter, air. The sound, whether 

 inflated with air or distended with water, had a diameter when fully 

 filled of 7 mm. at its widest point and a length of 12 mm. The 

 manometer was so arranged that the level of the mercury was as nearly 

 as possible that of the sound resting in the intestine. Occasionally 

 two sounds, each connected with a separate manometer, were used, one 

 being introduced through the upper, the other through the lower 

 mouth of the fistulous intestine. When it was desired to register the 

 speed of propulsion of a solid body through a portion or the whole of 

 the length of the fistulous intestine, a modified form of the method 

 used by Mosso, and developed in its details by Ranvier in experiments 

 upon the oesophagus, was employed. In this case the travelling sounds 

 were oblong bodies having rounded ends, and measuring in breadth 

 from 5 to 9 mm., in length 12 to 14 mm., and were made of metal, 

 cork hollowed out, or glass, and in several experiments a solid sound 

 was replaced by a small piece of lean meat. Those made of metal 

 were the thin- walled silver capsules which Prof. Kronecker employs 

 for the introduction of his maximal thermometers into the alimentary 

 canal of animals. They are perforated with one or two holes which 

 serve for the attachment of a thread of silk. The larger of the 

 metal capsules which I employed as a travelling sound was 9 mm. 

 broad by 14 long, and weighed 3*4 grams ; the smaller, 6 mm. by 

 14, weighed 2*2 grams. 



The registering apparatus consisted merely of a thin wedge of cork 

 bearing a glass pen, and travelling vertically by means of two glass 

 eyes passed through its substance upon parallel steel guides. The 

 weight of this falling pen was 2 grams. A fine silk thread from the 

 sound to the pen passed over two pulleys, one placed opposite and in 

 the same plane as the fistulous opening, the second vertically above 

 the steel guides of the travelling pen. When traction was made by 

 the sound the pen was drawn upwards, its elevation being directly 

 proportional to the extent of withdrawal of the sound from the lower 

 pulley. 



For each observation the dog was placed on its side with the 

 fistulous opening opposite to and at the same level as the lower pulley; 

 the sound was introduced into the upper fistulous opening, the upper 

 pulley raised so that the pen was drawn upwards for a few centimetres 

 from its support,* and the drum arranged so as to leave the whole 



* The respiratory movements were to some extent communicated to the pen con- 

 nected with the sound. By means of two Marey's tambours the number of respira- 

 tions was usually written at the same time as the curve of intestinal movement. 



