112 On the Use of the Cerebellum, &e. [Fkb. 



through the cerebellum upon the medulla oblongata, the muscles of 

 the body were at the same time convulsed. On pressing upon the 

 spinal marrow as it issues from the foramen magnum, the muscles 

 of the body were convulsed, those of the head and face re- 

 maining quiescent. The experiment has been frequently, and 

 several times in presence of my medical friends, repeated upon 

 sheep, rabbits, and dogs, with invariable success. This discovery 

 led to several minute dissections of the brain and spinal marrow in 

 dogs, cats, cows, horses, &c. ; in which I found that the spinal 

 marrow is uniformly composed of four longitudinal divisions — two 

 larger, anterior, which may be traced into the cerebrum, and two 

 smaller, posterior, which may be traced into the cerebellum. I 

 suppose that the two anterior portions are the organ of feeling ; the 

 two posterior, of motion. I also found that the spinal marrow does 

 not terminate at the sacrum in a lash of nerves, but tapers to a 

 sharp point, to the very extremity of which 1 could distinctly trace 

 the division into four portions. 



On tracing the various organs of the body from man downwards 

 through the chain of living beings, I find that there are three great 

 fundamental functions — respiration, nutrition, and propagation, 

 common to all organized beings. In all vegetables and animals 

 there are neither more nor less, in so far as the living machine is 

 concerned, than these three functions, every other being subsidiary. 

 From this view I was induced to think more highly of respiration 

 than as an absorber of oxygen, or an expeller of carbon. That such 

 a large complicated organ, and such a laborious and incessant 

 function, should serve no other purpose but drawing off carbon 

 from the blood, is neither consjgtent with analogy, nor with that 

 Divine wisdom and power which uniformly effectuates the greatest 

 ends by the smallest means. It appears to me that vitality has been 

 originally diffused equally over the creation; that vegetable and 

 animal life is just a less or greater accumulation of this vitality ; 

 and thai the leaves, gills, and lungs, are the chemical laboratory 

 in which vitality is continually secreted as fast as it is expended bj 

 the vital and animal functions. 



As the facts and arguments in support of this theory, and o*" the 

 preceding discovery, are forthwith to come before the public, in a 

 work to be entitled. Researches in Physiology and Physiognomy, I 

 will i)otat present encroach further on your patience. 



I remain, Sir, your most oljedient servant, 



John Cross. 



Article VI. 



Ohservatimis on Tanning. By Mr. Murray. 



(To iJr. Tliomson.) 



SIR, 

 NoTKiNCiin the Annals of Philosophjj, for the 1st of September, 

 Queries respecting Tanning, I presume the liberty o( submitting to 



