February 14, 1895] 



NATURE 



367 



was made and decarted or Iransferted from the vessel in which 

 1 was liquefied to another by means of a valve, and thereby 

 lendered capalile of use as a cooling agenr. In su|>port of ihis 

 as?eition, I call as witness Pro'. Charles Olszewski himself, 

 who states in the rhilosnphiial A/agazine, February 1895, 

 p. 189: "In 1SS3, and for several years following, I liquefied 

 the gases in a sirong glass tube." There is no sugce^ion made 

 that a steel cylinder and valve was used by Olszewski till the 

 yeir 1890. Whereas four years in advance I had u-ed a much 

 safer and I etiur form of apparatus, practically identical in prin- 

 ciple with that u-ed in Cracow in the year 1890. Have 1 ever 

 sugge led that Prof. Olszev/ski was aniicipated, or atiempied to 

 raite any question of piiority? Perhaps ihe critic will have 

 the audacity to say, in reply, this is no publicaiion, the J'lo- 

 <:'edings of the Koyal Intctiition, English and American science 

 f eriodicals, nt t 1 eing among-l the class of recognised scienlific 

 outnals. Well, if I am pleased to throw my bread upon the 

 waters, adopting the view that every truthfully recorded experi- 

 ment which appears in any journal associa'ed with my nau e is 

 public.iiion, suiely I should simply be conducting myself in the 

 *' too modest " way my critic commends. 



As a specimen of the distortion of facts to prove another case 

 of priority that is claimed, I find that MM. Charles Olszewski 

 and Augusie Witkowski, Membres Correspondants, presenting 

 their memoir " Proiriees opiique de I'oxygene liquide," on 

 October 3, 1S92, and, on referring to the paper, it is dated July 

 15, 1892, and the (iillowmg footnote is added : 



" Avant la publication cle notre comraanication, M^•. Liveing 

 et Dewar ont fait connaiire (Phil. Mag. Aout 1892), les 

 resultats de leurs rccherches sur la refraction des gaz liqucjiies." 



Yet the crilic says our experiments were ' marniy repetitions 

 o( the work of Olszew.-ki and Witkowski." The garbled extracts 

 selected to make it appear that I have been guilty of mis- 

 represi ntation are all of the same kind. . . . Thus I am taken 

 to task for using the expression in the lecture on liquid air, 

 of 1S93 : ** Having no recorded experience to guide us in con- 

 ducting such investigations, the best instruments and methods 

 of working have to be discovered." The next sentence runs as 

 follows : " The necessity of devising some new kind of vessel 

 for storing and manipulating exceedingly volatile fluids like 

 liquid oxygen and liquid air, became apparent when the optical 

 properties of the boclies came under'examination. Apart alto- 

 gether from the rapid ebullition interfering with the experi- 

 menlal work, the fact that it did take place involved a great 

 additional cost in the conduct of experiments on the properties of 

 matter under such exceptional conditioasof temperaiure." What 

 can be said in defence of such glarin.^ misrepresentation of the 

 meaning of my words ? Mr. .\I. M. Pattison Miiir's demand for 

 ^^ instant ami serious cottsiiieration" of his client's **case'' has 

 been quickly met. I trust the result will .... fit in with 

 his brief. James Dewar. 



Koyal Institution, February 12. 



[A few personal remarks in Prof. Dewar's letter have been 

 omitted, as they do not affect the points at issue. — 

 Ed. Nature.] 



Vertebrate Segmentation. 



Mr. H. G. Wells, in a recent number of Nati'rf, honours 

 my littie book by making it an example of a contravention of 

 what he regards as a principle of education. With that I have 

 no quarrel. But I must object to ihe insance he has chosen. 

 The sentences from wl ich he quotes refer to the phenomena of 

 segmentation common to coelomate tissues, and not to the 

 derivation of vertebrates from any invertebrate group. So far 

 from giving *'lhe impression almost in so many words — *cut 

 and dried,' and ready to be ca^t into the oven — that the verte- 

 brate type is merely a concentrated derivative (concertina 

 fashion) of the cfjeiopod type," I devote the chapter (xv.) 

 from which he has taken his quotations, to showing that the 

 earthworm ami the vertebrates merely belong to two out of the 

 many isolated groups; and at the end of the chapter (though 

 not in spaced type, as I did not consider the question of verte- 

 brate descent congruous with the aims of an elementary text- 

 book) I state that " the type common to the lowest members of 

 the groups of which the earthworm on the one hand, and the 

 vertebrates on the other, form the highest examples, is a simple 

 unsegmented ccvlomate animal." 



P. Chalmers Mitchell. 



The Black veined White Butterfly. 



Mr. KiRtv, on p. 340 of your last issue, says (in criticism 

 of Mr. Furneaux) that this insect "would not frequent open 

 ground at a distance from trees." I suppose there are not now 

 many Englishmen who have taken it in this country ; and it 

 nay be worth while to record that the common on which my 

 brother and I used to find it tolerably abundant in the years 

 1S5 7-1859, was quite an open place, with no adjacent «ood, 

 and very little hedge timber. This common is about a mile 

 and a half to the west of Cardiff ; I passed it in the train a few 

 weeks ago, and noted that it is being encroached on by 

 suburbs. We had many a hot chase there over gorse and briar, 

 and always considered this butterfly the most difficult of all 

 to catch. I have never seen it in England since 1859 or i860. 

 Oxford, February II. 



W. Warde Fowler. 



Parrots in the Philippine Islands, 



PraV allow me space to acknowledge a bad mistake which I 

 first made in the ninth editi. n of the " Encyclopsedia Bri- 

 lannica" (xviii. p. 322), and have lately repealed in the 

 "Dictionary of Birds" (p. 687), by asserting that | arrots are 

 ■'wanting in the Philippine Islands." Seeing that the article 

 was written more than ten years ago, it is quite out of my 

 power to account for the mi-statement : my only wonder is that 

 it has not been before challenged, since there is, and has been 

 for some cent ures, abundance of evidence to show that there 

 are plenty of parrots in that group of islands, which, indeed, is 

 as well furnished with them (as remarked by my friend Mr. L. 

 W. Wigleswoith, who has kindly drawn my attention to my 

 error) as is the island of Celebes and I had already (p. 93) 

 noticed the Philippine spec es of Cockatoo. 



Cambridge, February 9. 



Alfred Newton. 



TWENTY-FIVE YEARS OF GEOLOGICAL 

 PROGRESS IN BRITAIN. 



T OOKING back across ihe fourth part of a century in 

 •'— ' the progress of any branch of science, we naturally 

 turn first to the list of names of those to whose labours 

 that progress has been due, anci though many of these 

 names may happily still be counted among the living, we 

 note many a blank where the hand of death has thinned 

 the ranks. Perhaps in this country no department of 

 natural knowledge can boast a more illustrious bead roll 

 than that of Geology. The story of the earth had hardly 

 begun to be scientifically studied until the first decades 

 of the present century, and some of the early fathers of 

 geology lived on until well within the life-time of the 

 present generation. A curious transition has thus been 

 going on during the last five-and-tvventy years. On the 

 one hand, there have been moving amongst us geological 

 magnates who achieved their fame in the old days when 

 it was still possible for a man to possess a tolerablv full 

 personal knowledge of almost every department of the 

 science. On the other hand, around these few living 

 memorials of the heroic age, grew up hosts of younger 

 men, who, finding the main lines already traced for 

 them, have become in large measure specialists, devoting 

 themselves with enthusiasm, but with more restricted 

 vision, to one formation, or one group of rocks, or one 

 tribe of fossils. The days of broad outlines and rapid 

 generalisation have gone. No new systems remain to be 

 added to the geological record of these islands. No new- 

 assemblages of e.xtinct types of life now reward the 

 sedulous collector. We have entered upon the era of 

 minute detail and patient elaboration. The field-glass 

 has given way to the microscope. The advance of the 

 science must now be based on laborious research, less 

 brilliant no doubt in its immediate effect, but probably 

 not less lasting in its influence and its results. 



NO. 1320. VOL. 5 l] 



