NOTE-BOOK OF A NATURALIST. 217 



but is carried farther, even tliroiigli tlie whole body. In 

 the learned and observant Doctor's time, the nature of 

 the absorbent system was not so well known as it is in 

 ours, thouo-h there is a ofreat deal still to learn. 



Dr. Mead was of opinion that this universal communi- 

 cation was effected by the great activity of the nervous 

 fluid, one part of Avhich being infected immediately 

 tainted all the rest. Thus, according to his theory, the 

 whole system of nervous expansions is drawn into spasms 

 and convulsions ; and, according to the different nature 

 of the parts to which they belong, different symptoms 

 are produced. In the stomach and intestines, these 

 spasms cause sickness, vomitings, and gripes ; in the 

 brain, deliria, sleepiness, and epileptic fits ; in the heart, 

 intermissions of the arterial pulse, palpitations, and 

 swooniugs ; in the lungs, difficulty of breathing, with 

 strangling and suffocations ; in the liver, by the spasmo- 

 dic contraction of the biliary ducts the bile is returned 

 into the blood, and makes a jaundice ; in the kidneys, 

 the same disposition of the urinary canals interrupts the 

 secretion of the urine, and makes it quite irregular. In 

 short, as he says, the animal economy is all disturbed : 

 and though different poisons may show their most re- 

 markable effects in different parts, and these, according 

 to the violence of the hurt, may appear in different de- 

 grees, yet the symptoms always make it plain that the 

 first bad impression is made upon the animal spirits. 



When we presently come to consider the symptoms 

 that follow the bite of one of the venomous serpents — 

 the common viper for example — we shall find them 

 analogous to those that follow the seizures in plagues, 

 cholera, fevers, and other pestilential diseases, where 

 faintness, giddiness, palpitations of the heart, and all the 

 other disorders which show that the nervous system is 

 affected, are manifested ; and, in truth, the sufferer in 

 such cases is labouring under the effect of real poison. 



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