Morphology 



401 



fluid Park* gives the following directions: "The patient should lie on 

 the right side with the knees drawn up and the left shoulder de- 

 pressed. The skin of the patient's back, the hands of the operator, 

 and the large antitoxin syringe should be sterile. The needle 

 should be 4 cm. in length, with a diameter of i mm. for children, 

 and larger for adults. The puncture is generally made between 

 the third and fourth lumbar vertebrae. The thumb of the left 

 hand is pressed between the spinous processes, and the point of the 

 needle is entered about i cm. to the right of the median line and 



n 



Fig. 138. — Technic of spinal puncture. The patient is sitting on the edge 

 of a chair and is bent forward; the crests of the ilia are indicated by black lines, 

 and are on a level with the spinous process of the fourth lumbar vertebra;- 

 the "soft spot" is found just above. The first tube receives the first few drops of 

 fluid, which are usually blood tinged (Kolmer). 



on a level with the thumb-nail, and directed slightly upward and 

 inward toward the median hne. At a depth of 3 or 4 cm. in children 

 and 7 or 8 cm. in adults the needle enters the subarachnoid space, 

 and the fluids flow out in drops or in a stream. If the needle meets 

 a bony obstruction, withdraw and thrust again rather than make 

 lateral movements. Any blood obscures microscopic examination. 

 Adults, not too ill, may sit upon a chair or upon the edge of the bed 



'"Bacteriology in Medicine and Surgery," Philadelphia, 1899, p. 364. 

 26 



