164 Dispensatory of the United States. 



milk and water. Sometimes the leech is put into a large quill, open 

 at both ends, and applied, with the head to the skin, until it fastens 

 itself, when the quill is withdrawn. Leeches continue to draw blood 

 until they are gorged, when they drop off. The quantity of blood 

 which they will draw varies, according to the part to which they are 

 applied, and the degree of inflammation existing in it. Tn the loose 

 and vascular textures, they will abstract more than in those which 

 are firm and compact, and more from an inflamed than a healthy 

 part. As a general rule, our leechers apply six for every fluid ounce 

 of blood. A single European leech will draw from half an ounce 

 to an ounce. The quantity may often be much increased by bath- 

 ing the wound with warm water. Leeches will continue to suck, 

 after their tails are cut off, which is sometimes done, although it is a 

 barbarous practice. 



They may be separated from the skin at any time, by sprinkling 

 a little salt upon them. After they drop off, the same application 

 will make them disgorge the blood they have swallowed. Some 

 leechers draw the leeches, from the tail to the head, through their 

 fingers, and thus squeeze out the blood ; after which, all that is ne- 

 cessary is to put them in clean water and change it frequendy. 

 Leeches which are gorged with blood, should be kept in a vessel by 

 themselves, as they are more subject to disease, and often occasion a 

 great mortality among the others. They should not be again used, 

 until they have recovered their activity. 



In cases where the bleeding from leech-bites continues longer than 

 is desirable, it may be stopped by continued pressure, with the appli- 

 cation of lint, or by touching the wounds with lunar caustic. It may 

 sometimes be necessary, in the case of a deep bite, to sew the wound, 

 which is readily done with a single stitch of the needle, that need not 

 penetrate deeper than the cutis. 



To this valuable account of the Leech, we would add, that it ap- 

 pears to be necessary to guard them against sudden changes in the 

 electrical state of the atmosphere. That they are very susceptible 

 of these changes, and are often destroyed by them, appears to be a 

 well established fact, and from the experiments of M. Derheims of 

 St. Omer, their death is occasioned by a coagulation of the blood 

 by electricity. By placing the jar or vessel in which they are kept 

 near a good conducting substance, their preservation from this source 

 of danger might probably be secured. 



