NERVOUS TISSUE. 29 



of their several advocates they are all plausibly support- 

 ed. It is a singular fact in reference to contractility, 

 that though it is generally very strongly excited by the 

 electric fluid after death, yet it is entirely lost in a body 

 that has been killed by lightning in an animal that has 

 been run to death, or that has died from the operation 

 of poisons. It has also beea observed that the rapidity 

 with which putrefaction takes place after death is inverse- 

 ly in proportion to the powers of contraction which 

 remain in the muscles. But we must now hasten to the 

 nervous tissue. 



Emily. It is this, I presume, which compqses the 

 nerves, those curious organs that are so much concerned 

 in the operations of the mind. I promise myself much 

 gratification Irom your account of this tissue. 



Dr. B. It not only composes the nerves, but the 

 brain, spinal marrow and other important parts. It has 

 a soft, whitish, and pulpy appearance, but when properly 

 prepared it is observed to possess a fibrous structure 

 its fibres being arranged parallel to one another, as in 

 the muscular tissue. To the nervous tissue belongs the 

 general properly of sensibility, or the power of transmit- 

 ting impressions that are made on it, from one part 

 to another. This, however, is manifested in such differ- 

 ent ways that there appear to be distinct kinds of this 

 power. Thus, a wound in the head may be followed by 

 sickness of the stomach ; in which case, an impression 

 is communicated from one of these parts to the other 

 without the knowledge of the mind. This kind of sen- 

 sibility is the most common and the most essential to 

 life. By its influence, the various parts and organs of 

 the body are enabled to communicate together, and thus 

 a beautiful harmony is maintained through all their com- 

 plicated actions. Secondly ; an external object touches 

 the body and an impression is carried immediately to 

 the mind by /which it is made acquainted with the fact. 

 This h an instance of a second kind of sensibility and is 

 popularly termed sensation, but is more accurately distin- 

 3* 



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