SepL 19, 1878] 



NATURE 



539 



is published by the Committee of the Palestine Explora- 

 tion Fund, but is merely preliminary to the publication of 

 the various detailed memoirs and the unprecedentedly 

 minute map which are in preparation. It is taainly the 

 narrative of Lieut. Conder's personal wcrk and adventure, 

 but besides its strong interest as a record of adventure in 

 one of the most interesting countries in the world, it con- 

 tains a vast amount of information and discussion con- 

 cerningthe many places so full of sacred associations to all 

 Christian peoples. The work of the Survey was often pur- 

 sued under considerable hardships, and occasionally at 

 some risk, and more than one of the staff had to succumb 

 during the progress of the work. It is evident that this most 

 interesting of surveys has been executed with a minute- 

 ness and a care that leave little to be desired. The 

 survey was actually commenced at the end of the year 

 1871. Capt. Stewart, the first officer in charge, had to 

 come home on account of his health, and in July, 1872, 

 Lieut. Conder took up the command, and completed 

 four-fifths of the survey, the remaining fifth being carried 

 out in 1877 by Lieut. Kitchener. The great map now 

 extends over 6,000 square miles, from Dan to Beersheba, 

 and from the Jordan to the Mediterranean Sea. This map 

 is being prepared in twenty-six sheets ; and an idea of its 

 minuteness may be obtained from the fact that it will show 

 tombs, caves, cisterns, wells, springs, rock-cut wine-presses, 

 remarkable trees, and even the Roman milestones. Ac- 

 companying the map will be a memoir prepared by Lieut. 

 Conder under the direction of Major Wilson and Mr. 

 George Grove. It is hoped that all will be ready for 

 publication in the course of a few months. This memoir 

 will contain a vast collection of varied information 

 gathered from many sources, and with the map will 

 undoubtedly be of infinite service to students of the 

 Biblical narratives. Lieut. Conder's work will amply 

 repay careful study, and the many illustrations of places 

 whose names are "familiar as household words," add 

 greatly to its interest and value. 



LETTERS TO THE EDITOR 



\Tke Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he tmdertake to return, 

 or to correspond with the writers of rejected manuscripts. 

 No notice is taken of anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com' 

 munications contaitting interesting and novel facts."] 



Discovery of Vulcan 



A LETTER from the Astronomer-Royal, in Nature, vol. xviii. 

 P' 380, giving the exact position of d Cancri on the day of 

 the total solar eclipse, intimates that, as the position given by 

 Prof. Watson of the intra-Mercurial planet discovered on that 

 day agrees so closely with that star, it may have been the 

 object discovered, I have thought it advisable to give the facts 

 concerning it, in order to correct such an impression if it still 

 exists. That he had a view of the planet as stated there is no 

 doubt, for I myself saw it some four or five minutes later, using 

 fl as a comparison star, and am able not only to corroborate 

 the discovery, but to substantiate the position given by him. 

 Its proximity to d enabled me to estimate its position with 

 great exactness, especially in declination. It may be well here 

 to state that I was prevented from searching to the east of the 

 sun, in consequence of forgetting to untie a string with which I 

 had tied, to the eye end of the telescope, a long pole to prevent the 

 wind firom shaking it, the end resting on the ground not allowing 

 the instrument to be moved to the eastward. It is undoubtedly 

 to this circumstance, which at the time seemed untoward, that I 

 owe the discovery of Vulcan. In my eagerness to discover this 

 hypothetical planet I had decided to ignore nearly all of the phe- 

 nomena attending the eclipse, and as, at the commencement of 

 total phase, there was visible neither the chromosphere nor any 

 protuberances — nothing, in fact, but the corona, I almost im- 

 mediately began the sweeps for it ; but my hampered telescope 

 behaved badly, and no regularity in the sweeps could be main- 



tamed. Almost at once my eye caught two red stars about 

 3° south-west of the sun, with large, round, and equally brio-ht 

 discs, which I estimated as of the fifth magnitude, appeanno- 

 (this was my thought at the time) about as bright in the tele"^ 

 scope as the pole star does to the naked eye. I then carefully 

 noted their distances from the sun and from each other, and the 

 direction in which they pointed, &c., and recorded them in my 

 memory, where, to my mind's eye, they are stiU distinctly 

 visible. I then swept southward, not daring to venture far to 

 the west for fear I should be unable to get back again, and 

 soon came upon two stars resembling in every particular the 

 former two I had found, and, sighting along the outside of the 

 tube, was surprised to find I was viewing the same objects. 

 Again I observed them with the utmost care, and then recom- 

 menced my sweeps in another direction, but I soon had them 

 again, and for the third time in the field. This was also the 

 last, as a small cloud hindered a final leave-taking just before 

 the end of totality, as I had intended, I saw no other stars 

 besides these two, not even 5, so close to the eastern limb of 

 the sun. ITie distance between them was about 7' or 8'. 



By three careful estimates the two stars pointed exactly 

 to the sun's centre. When it is considered that a deviation of 

 not over 15", in two objects so close, will cause them to point 

 considerably to one side of the centre of the sun— three degrees 

 away— it maybe assumed that its dechnation was quite correctly 

 estimated. Thus far all seems clear and free from doubt, but 

 it is just here where the trouble begins, for, unfortunately, I 

 could _ not tell which was the star and which the planet. 

 Happily Prof. Watson comes to the rescue, and with his means 

 of measuring, says " the planet was nearest the sun," 



The Astronomer-Royal gives the place of e, on that day, 

 as in R,A, 8h, 24m. 40s., Decl. -t- 18° 30' 20", From this I 

 deduce the position of the planet at 5h. 22m. Washington M.T. 

 to have been in 



R.A. 8h. 26m. 40s, 

 Decl. 4- 1 8* 30' 25", 



This is a close approximation to that given by Prof, Watson.. 

 It is to be hoped that a comparison will determine the position 

 in its orbit, whether it was approaching superior conjunction, as 

 Watson thinks, or, as appears most reasonable to me, had just 

 passed its inferior conjunction. Lewis Swift 



Rochester, N. Y. September 4 



The Respiration of Plants 



I DESIRE, with your permission, to give publicity in the 

 columns of Nature to the results of some observations on the 

 above subject, communicated by me to the Royal Society cf 

 Victoria on June 13. As the facts to be mentioned are not re- 

 ferred to in Sachs' " Text-book of Botany," in the dictionaries 

 of chemistry of Watts and Wurtz, or in recent volumes of the 

 Journal of the Chemical Society or the Chemisches Centralblatt, I 

 presume that they are little, if at all, known to botanists. ' I 

 have found, first about nine years ago, and have more system- 

 atically observed lately, that fresh sections of many fruits, such 

 as the apple and pear, and other vegetable structures as the 

 potato, turnip, &c., give the reactions considered to be 

 characteristic of ozone, viz., causing separation of iodine 

 from iodide of potassium, and turning tincture of guaiacum 

 blue, the intensity of these reactions varying in different 

 samples of the vegetable substances, but depending mainly on 

 their comparative freshness. I have further found that the sair.c 

 structures contain a substance which acts as an Ozontrdger, to use 

 Schonbein's expression, a substance which transfers ozone from 

 peroxide of hydrogen and similar articles. This is shown by 

 the fact that if the guaiacum is not blued at all, or only to a 

 slight extent, the blue colour becomes very marked when a drop 

 of ethereal solution of peroxide of hydrogen is added, I infer 

 from these observations (l) thatthe oxygen irJialed by living plants, 

 and even by pulled fruits for a time, is ozonised or rendered 

 active, probably by entering into loose combination, as is the 

 case with the oxygen in the blood of animals ; and (2) that it is 

 probable, though not proved, that the ozone-transferring sub- 

 stance existing in almost every fresh vegetable structure is that 

 with which it is loosely combined, as the oxygen in the bleed 

 is with the haemoglobin of the red corpuscles, which is a 

 very active Ozontrdger. This element in plants is gradually 

 destroyed as decay comes on, and ceases to perform its 



