I beg to say that in my opinion the use of tobacco is, in the great majority of cases, prejudicial. As to alcohol, I would rather not express any opinion. JOHN LUBBOCK. February 17, 1882. PROFESSOR MAGNUS. In reply to your enquiry respecting the use of tobacco and alcohol, I shall be glad to give you all the information I possess on this subject; though, of course, I am not in a position to judge whether my few remarks will be of any service to you. In the first place, as regards the influence of tobacco and alcohol upon the health in general, it is clearly ascertained that under certain circumstances, it may become highly injurious. Apart from the disturbance produced in the whole nervous system, there are serious diseases affecting certain organs of the body, which arise solely from the abuse of both these stimulants. We note a serious affection of the visual organs, which we plainly designate by the name of: "Emblyopia ex abusu nicotiano et alcoholico." The symptoms of this complaint consist chiefly in a gradual and steady decline of the power of sight, coupled with partial colour blindness. I cannot here enter into details as to the manner in which the range of sight is affected as regards each of the different colours, and can only refer to the characteristic weakening of the power to distinguish red from other hues. It will not be necessary, I presume, to extend my remarks to the evil effects of tobacco and alcohol upon the human body, as you are sufficiently acquainted with them, especially as far as alcohol is concerned. Now as to the relation in which both stand to mental work. If I may be allowed to state first of all the result of observations in my own case, I must tell you that I have not found these drugs to be in any degree helpful in the performance of mental labour. I find it absolutely impossible to put any sensible thoughts on paper when I am smoking. In former years I frequently tried to smoke a pipe or a cigar over my work, but had always to give it up; I only got into proper working condition after putting tobacco aside. Indeed, of late years I have felt a growing antipathy to tobacco, so that, whilst I was formerly passionately fond of smoking, I new, very rarely, indeed, indulge in the practice. My experience with regard to alcohol is precisely similar. I am very fond of a little beer, but not when at work. The current of my thoughts flows much more clearly and rapidly when I have had no drink. I have a special aversion for wine, which, indeed, I do not drink at all. Generally speaking, I can therefore say, that, in my own case, tobacco and alcohol have a disturbing effect, when doing mental work. This you will, of course, take as applying to myself alone. I know some very respectable scholars in this town and neighbourhood who are only capable of thinking and working properly when under the influence of tobacco. MAGNUS. Breslau, February 28, 1882. MR. EDWARD MAITLAND, B. A.