I regret that it is not in my power to give you the information you ask. I have not made the question a study, and have no fixed opinion about it. All that I can say is that I have never made use of alcohol in any form as an essential stimulant. Coffee suits me much better. Alcohol, so far as I can judge, is good only as a physical stimulant after great physical fatigue, and even then it should be taken in very small quantities. As for tobacco, I have the bad habit of smoking cigarettes, and find them useful between two ideas,--when I have the first but have not arrived at the second; but I do not regard them as a necessity. It is probable that there is a little diversion produced at the same time, a little excitement and exhilaration. But every custom of this kind becomes tyrannical, and the observations which accompany your letter are very judicious. Among the men of letters and men of science around me there is not one to my knowledge who in order to think and to write has recourse to spirituous liquors; but three-fourths of them smoke, and almost all take before their work a cup of coffee. I have seen English journalists writing their articles by night with the aid of a bottle of champagne. With us, the articles are written in the day time, and our journalists have, therefore, no necessity to resort to this stimulant. H. TAINE. March 28, 1882. MR. ANTHONY TROLLOPE. I have been a smoker nearly all my life. Five years ago I found it certainly was hurting me, causing my hand to shake and producing somnolence. I gave it up for two years. A doctor told me I had smoked too much (three large cigars daily). Two years since I took to it again, and now smoke three small cigars (very small), and, so far as I can tell, without any effect. ANTHONY TROLLOPE. Feb. 11, 1882. SIR WILLIAM THOMSON, M. A., LL. D., D. C. L., F. R. S. The question of usefulness or the reverse of tobacco or alcohol is one of health, and to be answered by medical men, if they can. It seems to me that neither is of the slightest consequence as a stimulus or help to intellectual efforts, but that either may be used without harm or the reverse if in small enough quantities, so as not to hurt the digestion. WILLIAM THOMSON. Feb. 13, 1882. PROFESSOR TRANTMANN, BONN UNIVERSITY. I am not a smoker, so that I am unable to make any statement regarding the effect of tobacco. As to alcohol, I never make use of spirits in order to stimulate my brain, but often, after working hard, I drink a glass of beer or wine, and immediately feel relieved. M. TRANTMANN. March 14, 1882. PROFESSOR TYNDALL, LL. D., F. R. S.