THE ABDOMEN, 31 



an aneurysm below it, is proved by recorded cases, and by 

 none more effectually than by a case related in the second 

 volume of the ' Reports of St. Bartholomew's Hospital.' 



It may be asked, why not apply pressure on the aorta 

 above the umbilicus ? The answer is, that the aorta above 

 the umbilicus is farther from the surface, and is, moreover, 

 covered by important structures upon which pressure would 

 be dangerous. 



63. Parts behind linea alba. Let us next consider what 

 viscera lie immediately behind the linea alba. For two or 

 three ringers' breadth below the ensiform cartilage there is 

 the left lobe of the liver, which here crosses the middle line. 

 Below the edge of the liver comes the stomach, more or less 

 in contact with the linea alba, according to its degree of dis- 

 tension. In extreme distension the stomach pushes every- 

 thing out of the way, and occupies all the room between the 

 liver and the umbilicus. When empty and contracted, it 

 retreats behind the liver, and lies flat in front of the 

 pancreas at the back of the abdomen ; thus giving rise to the 

 hollow termed the 'pit of the stomach.' But as the stomach 

 distends, it makes a considerable fulness where there was a 

 pit. The middle of the transverse colon lies above the um- 

 bilicus, occupying space (vertically two or three inches) 

 according to its distension. Behind and below the umbilicus, 

 supposing the bladder contracted, are the small intestines, 

 covered by the great omentum. 



64. Peritoneum. The peritoneum is in contact with the 

 linea alba all the way down to the pubes, when the bladder is 

 empty. But when the bladder distends, it raises the peri- 

 toneum from the middle line above the pubes ; so that with a 

 bladder distended half-way up to the umbilicus, there is a space 

 of nearly two inches above the symphysis where the bladder 

 may be tapped without risk of injury to the peritoneum. For 

 the same reason, we have space sufficient for the successful 

 performance of the high operation for stone. This fact in 

 anatomy must have been well understood by Jean de Dot, the 

 smith at Amsterdam, who, in the seventeenth century, cut 

 himself in the linea alba above the pubes, and took out of his 



