302 ESSAYS and' OBSERVATIONS 



of motion, not only in the parts to which, 

 it is applied, but thro' the whole body. 

 N° I, 2, 3, 8, II & 22. 



(b) Opium produces thefe efFefts much 

 more quickly in animals which are foon killed 

 by want of food and air, than in thofe which 

 can live long without them, and the parts of 

 whofe bodies preferve a power of motion 

 and appearances of life for a confiderable 

 time after they are feparated from each 

 other. N° i, 3, &c. compared with N°2i, 

 22 & 23. 



; (c) Since a folution o^ opium injeded into 

 the ftomach and guts deftroys the fenfibility 

 and moving power of frogs, fully as foon 

 when they are deprived of their heart, as when 

 this organ remains untouched ; it follows, 

 that opium applied to thefe parts, does not 

 produce its effeds by entering the blood, and 

 being, by its means, conveyed to the brain, 

 as fome have imagined, but by its imme- 

 diate adtion on the organs and parts which 

 it touches. N° i. compared with N° 2. 

 See alfo Edinburgh Medical EJJays, edit. 3. 

 vol. 5. part I. page 140. 



(d) Since, after decollation and the de- 

 ftruftion of the fpinal marrow, opium ope- 

 rates 



