I cannot myself imagine any such condition of things as the supposed primitive solar nebula as possibly coming into existence under any conceivably antecedent conditions, but, granted that it did come into existence, it seems to me that the gaseous state must almost instantly begin changing into the solid state. Hence I adopt the meteoric theory instead of the nebular; since all the evidence is in favour of solid matter being abundant all through known space, while there is no evidence of metallic gases existing in space, except as the result of collisions of huge masses of matter. Is my difficulty a mare's nest?--Yours very truly, ALFRED R. WALLACE. * * * * * TO Mrs. Fisher _Broadstone, Wimborne. February 28, 1905._ Dear Mrs. Fisher,--Thanks for your letter. Am sorry I have not converted you, but perhaps it will come yet! I will only make one remark as to your conclusion. I have not attempted to prove a negative! That is not necessary. What I claim to have done is, to have shown that all the evidence we have, be it much or little, is decidedly against not only other solar planets having inhabitants, but also, as far as probabilities are concerned, equally against it in any supposed stellar planets--for not one has been proved to exist. There is absolutely no evidence which shows even a probability of there being other inhabited worlds. It is all pure speculation, depending upon our ideas as to what the universe is for, as to what _we_ think (some of us!) _ought_ to be! That is not evidence, even of the flimsiest. All I maintain is that mine _is_ evidence, founded on physical probabilities, and that, as against no evidence at all--no proved physical probability--mine holds the field!--Yours very truly, ALFRED R. WALLACE. * * * * * TO MR. E. SMEDLEY _Broadstone, Dorset. July 24, 1907._ Dear Mr. Smedley,-- ... I write chiefly to tell you that I have read Mr. Lowell's last book, "Mars and its Canals," and am now writing an article, or perhaps a small book, about it. I am sure his theories are all wrong, and I am showing why, so that anyone can see his fallacies. His observations, drawings, photographs, etc., are all quite right, and I believe true to nature, but his interpretation of what he sees is wrong--often even to absurdity. He began by thinking the straight lines are works of art, and as he finds more and more of these straight lines, he thinks that proves more completely that they are works of art, and then he twists all other evidence to suit that. The book is not very well written, but no doubt the newspaper men think that as he is such a great astronomer he must know what it all means! I am more than ever convinced that Mars is totally uninhabitable....--Yours very truly, ALFRED R. WALLACE. * * * * * TO PROF. BARRETT _Broadstone, Wimborne. August 10, 1907._