Feb. 7, 1884] 



NA TURE] 



be became acqnainted only much later through Dan\ in's books. 

 Thus it appears that between 1840 and 1850, in three at least of 

 the six universities of Prussia, Spren^el's \\<^x\■■. had fallen into 

 the most complete oblivion. Now it is improbable in the highest 

 degree that the several professors of natural history in these 

 universities sh .uld have ceased, unanimously and at the very 

 same time (1S41) lo teach what, between 1830 and 1840, they 

 had taught "a^ well known facts of the highest importance." 

 Hagen's statement, therefore, needs s?me further proof before 

 it can be accepted. 



If in Germany Sprengel's discoveries had been "well known 

 t>i every naturalist during the whole century," the opinion that 

 his treatise had been unduly neglected until it was, as it were, 

 re-discovered by Dar«in, could never have prevailed, as it 

 appears to do, among German bitanists, and Prof. Eduard 

 Strasburger could never have written the following lines, with 

 which I may appropriately conclude this letter: "Until i860 

 and some years afterwards in any catalogue of old botanical 

 l)Ooks, the work of Conrad Sprengel, published in 1793, 'Das 

 eiitdeckte Geheimniss der Natur im Bau und in der Befruchtung 

 der Blumen ' might be found at the price of about 15 sgr. 

 {\s. 6(/.), and I myself bought it there at that price as a curiosity, 

 lor the sake of its strange title. In the 220th cat.ilogue of 

 Friedlander (1S73) the price of the same book is 3 thlr. 20 sgr. 

 (lU.) This rise in the price of Sprengel's book shows very 

 strikingly the change through which in the meantime it has 

 passed in our appreciation. Fur only during the la:-t ten 

 years, after it had remained wholly unnoticed for nearly seventy 

 years, the old book has come to be duly valued. It was Charles 

 Darwin, who by his excellent book on Orchids . . . revived 

 ihe questions treated by Sprengel " (y £-«««• Z/to«/;»- .?t7/««^, 

 1S74, article 140.) Fritz MiJLLER 



Blumenau, Santa Catharina, Brazil, December 15, 1883 



Diffusion of Scientific Memoirs 



Prof. Tait appears to have misunderstood my object in 

 writing the letter published in your is-ue of January 24 (p. 287). 

 It refers distinctly to his letter of December 27, and not directly 

 t'l the review which began the correspondence. In that letter 

 Prof. Tait stated publicly that he had n t received certain pub- 

 lications of the Cambridge Philosophical Society. I desired, 

 as secretary, to explain that it was not due to the neglect of the 

 officers of the Society. He also says : — " Nature would do a 

 real service to science by collecting stati>tic5 as to the numbers 

 of different centres ... at which the Transactions of various 

 scientific societies were freely accessible in 1883 (say) and also 

 in 1853." It was in my power to give the statistics for " Tians- 

 actions or Proceedings or both" for the year 1S83 ; in answer to 

 I'.art of Prof. Tait's suggestion I did so. There is no reference 

 in my letter to the year 1854, so that Prof. Tait is not correct in 

 staling (Nature, January 31, p. 311) that the question between 

 us is, " What was the state of matters in 1854?" The year 

 1869 was the earliest for which, with the data ready lo hand, I 

 could obtain the numbers, I therefore gave statistics for that 

 year in addition ; I had no knowledge of what may have been 

 Ihe case in 1854, and I said nothing al)0ut it. Prof. Tait re- 

 ferred to a malady and suggested a cure. I merely wished to 

 show that the cure had already been applied. My remarks were 

 addressed solely to that point, and were not " beside the ques- 

 tion." Prof. Tait, in your last issue, has an elaborate argument 

 to prove that about one-third of the centres receiving publica- 

 tions receive Proceidings only. In this he is entirely mistaken. 

 At present the number of such centres is 6 ; in 1854 it was 

 o. The history of the case is as follows. Until the year 

 1843 the Cambridge Phdosophical Society published no Proceed- 

 ings. Between that year and 1864 short accounts of the papers 

 read and of the discussions were published in the Phil. 

 Mag., and separate coines were supplied to Ihe Society. In 

 1864 these were collected, and form vol. i. of the Pro- 

 ceedings. At the time they were not circulated separately ; 

 circulation was given them in the Phil. Mag. In that year 

 the arrangement with the Phil. Mag. came to an end, and 

 notices of the same kind v ere printed by the secretaries 

 and distributed to resident Felloius. Almost without an ex- 

 ception all the important papers published by the Society 

 appeared in the Transactions. There was no need therefore to 

 circulate Proceedings, and it was not done. This practice was con- 

 tinued upto 1876, when thesecond volume of the Proceedings was 

 cloed, and a new system begun. Thus up to 18760// centres re- 



ceiving publications necessarily received Transactions, and as a 

 matter of fact nothing else. A few copies of vols. i. and ii. of the 

 Proceedingshayesmceheen issued. Vol. iii. of the/';-i;(-«Vi//K^jwas 

 commenced in 1876, and both it and succeeding volumes contain 

 in full the .-horter <u- the less important communications made to 

 the Society, as well as abstracts of matter published in full in 

 the Transactions. Vols. iii. and iv., then, of lhe/'/(;ctwr'/«^xhave, 

 as a general rule, been sent with the Transactions, and Ihe 

 centres have usually, since 1S76, received both. Within the last 

 few years, how ever, 6 centres have been added to the list which 

 receive the Proceedings only. Thus in 1883 (omitting the 

 honorary Fellows) 114 centres received Transactions only, or 

 Transactions and Proceedings, in most cases the latter, and 6 

 received Proceedings only ; while in 1853 all the publications 

 distrilitited were Transactions. I do not jiretend to know what 

 the number of centres w as at that date, and my first letter made 

 no direct reference to it. Nothing in that letter, however, 

 supports the arguments adduced by Prof. Tait to prove that "it 

 follows from Mr. Glazebrook's data that the number of centres in 

 1854 must have been about 40 only." 



R. T. Glazebrook, 

 Secretary of the Cambridge Philosophical Society 

 Cambridge, February 4 



Brooks' Comet 



I SEND you a sketch of Brooks' comet, in which an attempt 

 is made to represent a remarkable change which took place in 

 the comet about January 13. On that evening the well- 

 defined and almost circular envelope which is represented 

 in the figure was entirely wanting w hen the comet was seen on 

 previous occasions. The nucleus was much more condensed 

 and star-like than at any time before. The envelope was of 

 nearly uniform brightness, with a perfectly defined outline, 

 which was easily measured. It seemed to be produced by two 

 fan-shaped emanations from the nucleus, which, curving back- 

 ward toward each other, met at the outer edges, leaving a darker 

 elliptical space on each side of the nucleus, the space on Ihe 

 north side being the darker, and the iireceding fan-shaped por- 

 tion having an extensi-jn on the north side. A line drawn 

 through the middle of the dark spaces would be perpendicular 

 to the axis of the tail. 



The diameter of this envelope was i' 20", while the diameter 

 of the outer nebulous envelope, as far as it could be readily traced, 

 was about 6' 9". The spectroscope showed a bright continuous 

 spectrum, which was surprisingly strong in the red, which com- 

 vdetely masked any lines. As the comet had not been seen here 

 for several days previous to the I3lh, thi^ appearance may have 

 been of considerable duration. Clouds prevented another view 

 until J'anuary 17, when the inner envelope had entirely lost its 

 sharp outline, and Ihe following portion had disappeared, leav- 

 ing a corresponding dark space, while the preceding portion had 

 increased its angular dimensions and revolved through an angle 

 of about 60°. 



This is the appearance it presented, though the change may 

 have occurred in a very different manner. The 26- inch equa- 

 torial did not bring out any additional details. The distance 

 from the following side of the nucleus to the outer edge of Ihe 

 inner envelope was about 32", whereas it had been 40" on the 

 13th, taking half the diameter of the envelope on that occasion 

 to represent the corresponding measurement on the 17th. 



A very marked increase in the length of the tail of the comet 

 occurred between December 27 and 28. For about one-third 

 of its length the tail was broad and fairly uniform in brightness ; 

 from the middle of this broad portion issued two long bright 

 streams, one being longer and brighter than the other. The total 

 length was about 4°. W. T. Sampson 



Naval Observatory, Washington, January 19 



" Mental Evolution in Animals" 

 The appearance of Mr. Romanes' new book with the above 

 title reminds me of a reference in his work on "Animal In- 

 telligence" loan observation of my own. I have intended for 

 at least twelve months past to write you about the mailer, but as 

 Mr. Romanes' new book is practically a continuation o his 

 former work, you will probably not conclude that 1 have 

 procrastinated too long. 



On page 251 of "Animal Intelligence" Mr. Romanes quotes 

 my story of a skate in the Manchester Aquarium. The fish in 



