Your favor of Dec. 28. is duly recieved. it gladdens me with the information that you continue to enjoy health. that is a principal mitgation of the evils of age. I wish that the situation of our friend Mr Adams was equally comfortable. but what I learn of his physical condition is truly deplorable. his mind however continues strong, and firm, his memory sound his hearing perfect, and his spirits good. but both he and myself are at that term of life when there is nothing before us to produce anxiety for it’s continuance. I am sorry for the occasion of expressing my condolance on the loss mentioned in your letter. the solitude in which we are left by the death of our friends is one of the great evils of protracted life. when I look back to the days of my youth it is like looking over a field of battle. all, all dead! and ourselves left alone amidst a new generation whom we know not, and who know not us.

I thank you beforehand for the book of your friend P. Vreede of which you have been so kind as to bespeak a copy for me.—on the subject of my porte-feuille be assured it contains nothing but copies of my letters. in these I have sometimes indulged myself in reflections on the things which have been passing. some of them, like that to the Quaker to which your letter refers, may give a moment’s amusement to a reader, and from the voluminous mass, when I am dead, a selection may perhaps be made of a few which may have interest enough to bear a single reading. mine has been too much a life of action to allow my mind to wander from the occurrences pressing on it.

I have been lately reading a most extraordinary book, that of M. Flourens on the functions of the nervous system, in vertebrated animals. he proves by too many, and too accurate experiments, to admit contradiction, that from such animals the whole contents of the cerebrum may be taken out, leaving the cerebellum, and the rest of the system uninjured, and the animal continue to live, in perfect health, an indefinite period. he mentions particularly a case of 10½ months survivance of a pullet. in that state the animal is deprived of every sense, of perception intelligence, memory and thought of every degree, it will perish on a heap of grain, unless you cram it down it’s throat. it retains the power of motion, but, feeling no motive, it never moves unless from external excitement. he demonstrates in fact that the cerebrum is the organ of thought, & possesses alone the faculty of thinking. this is a terrible tub thrown out to the Athanasians. they must tell us whether the soul remains in the body in this state, deprived of the power of thought? or does it leave the body, as in death? and where does it go? can it be recieved into heaven while it’s body is living on earth? these and a multitude of other questions it will be incumbent on them to answer otherwise than by the dogma that every one who believeth not with them without doubt shall perish everlastingly. the Materialist, fortified by these new proofs of his own creed, will hear with derision these Athanasian denunciations. it will not be very long before you and I shall know the truth of all this, and in the mean time I pray for the continuance of your health, contentment and comfort.

Th: Jefferson