Medicinal Leeches. 389 
plates, at five francs upon common paper. In an economi- 
eal point of view this process deserves to be recommended. 
s—lbid. 
{Other extracts from Foreign Journals.} 
93. Medicinal Leeches.*—A report has lately been laid be- 
fore the French Academy of Sciences, by MM. Duniéril and 
Latreille, on a memoir by MM. Pelletier and Huzard, jun., 
containing researches upon leeches. 
The authors of this memoir had been commissioned to ob- 
tain information for the civil authorities relative to the means 
of putting an end to the complaints which are often made to 
them respecting the bad quality of the leeches employed in 
medicine. The two chiei points which they proposed to ex- 
amine, are, Ist, 'Toascertain the causes which in certain cases 
render the little wounds made by these animals difficult to 
cure. 2dly, To examine the circumstances under which cer- 
tain leeches do not penetrate the skin to which they are ap- 
plied. On the first point authors agree with physicians in 
acknowledging that the inconveniences ascribed to leeches 
ought most frequently to be attributed either to the tempera- 
ment of the patient, or to the nature of the malady, or the 
means employed to detach them from the wound, cr to the 
foreign substances employed for staunching the blood and 
closing the wound. With regard to the second point, MM. 
Huzard and Pelletier have found that there are offered for 
sale species of leeches that at first sight entirely resemble 
medicinal leeches, but which differ from them completely ; 
ist, in their want of the serrated instrument proper to make 
the incisions in the skin, from which issues the blood that the 
animal sucks; 2dly, in the conformation of their stomach and 
the intestinal canal. The experiments of the authors have 
proved to them that the spurious leeches cannot be employ- 
* This article, and the next succeeding, are copied from the London 
Philosophical Magazine and Journal. 
