Sept. ir, 1879] 



NATURE 



455 



variance with the text, the text with itself. Hence, to 

 quote a few out of innumerable instances, such alterna- 

 tives as Yezd and Yuzd, Dalaki and Dulukee, M.ahamadan 

 and Mahomedan, Geeach and Giach, Tabaz and Tubbuz, 

 Ghain and Ghaeen. Then such old friends as Meshed, 

 Bushire, Turcoman, Hari-rud, disguised as Mushud, 

 Bushuhr, Turkmun, Hurri Rood, without any conceivable 

 advantage. It may be stated that owing to these eccen- 

 tricities the spelling in the passages here quoted has 

 necessarily been reduced to system. 



A. H. Keane 



OUR BOOK SHELF 



Catechism of Agricultural Chemistry and Geology. By 

 the late J. F. W. Johnston. An Entirely New Edition, 

 Revised and Enlarged by C. A. Cameron, M.D. 

 Seventy-eighth Thousand. (Edinburgh and London : 

 Blackwoods, 1879.) 



This popular and useful little book has been decidedly 

 improved by the additions and alterations which Dr. 

 Cameron has made. Since the author's death, about a 

 quarter of a century ago, this catechism had been once 

 revised (in 1863) by Dr. Voelcker, but the time had long 

 since arrived for further changes. If the present editor had 

 been less scrupulous in adhering to the original form and 

 substance of Prof. Johnston's work, this issue would have 

 justly merited the description on the title-page of " An 

 entirely new edition, revised and enlarged." There are, 

 it is true, two fresh pages in the present edition, corre- 

 sponding to a few new tables of the composition of cattle 

 foods, but we fail to find the numberless small changes 

 and additions which the progress of science demanded. 

 Every sentence of the book should have been rigorously 

 scrutinised and thoroughly amended, or even excised, 

 where necessary. All expressions such as these : " Rancid 

 butter is said to be sweetened" (p. 73), " It is said that 

 if a cow be liberally supplied with whey " (p. 74), " The 

 feeding with whey thickened with meal is said" (p. 74), 

 should be removed. Statements of which the teacher is 

 not sure should not find a place in an elementary cate- 

 chism. Again, the table, on p. 34, of the ash-constituents 

 removed from an acre by various crops needs emendation. 

 On turning to page 53 we find two other tables showing 

 the produce of corn and straw in certain field experiments 

 with various manures. We do not think the omission of 

 these tables would entail any loss, while their place might 

 be profitably occupied by a series of'conclusions deduced 

 from the really satisfactory experiments on crops made at 

 Rothamsted or at some of the continental agricultural 

 stations. For, indeed, what lesson can be learnt from the 

 statement (p. 53) that in an unnamed locality, on an un- 

 described soil, during a season of which the rainfall and 

 temperature are unrecorded, and by the use of a wheat 

 manure the composition of which is not furnished to the 

 reader, 42 bushels of wheat were produced per acre ? 

 Without duplicates and without repetition in different 

 locaUties and in different seasons, field-trials of manures 

 are positively misleading. But when once such tables as 

 those on pages 34 and 53 have got into a popular work 

 and remained there fifteen years, they have a good chance 

 of remaining fifty. 



The statement on p. 67 that parsnips contain no starch 

 will not stand, while we conclude that it was by some over- 

 sight that a tabular account of the constituents of various 

 root-crops has been omitted by Dr. Cameron in re-casting 

 and amplifying the data given by Dr. Voelcker in pre- 

 vious editions on page 65. We note here that question 

 363 on page 63 is repeated in question 374 on page 67, 

 and that the statistics (p. 74) of cheese production in the 

 United Kingdom are no longer correct. 



LETTERS TO THE EDITOR 



[ The Editor does net hold h imself responsible for opinions expressed 

 by his correspondents. Neither can he undertake 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. J he pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com- 

 munications containing interesting and novel facts.] 



Palisa's Comet 



I INCLOSE an ephemeris of the comet which was discovered 

 at Pola by Herr Palisa on August 21, thiaking that it may be of 

 interest to some of your readers. 



The ephemeris is calculated from observations made at my 

 observatory on the nights of August 26, 27, and 28, by Dr. R. 

 Copeland and Herr Lohse. 



The comet is easily visible in a 4-inch telescope. 



Berlin 

 midnight. 

 Sept. 5 . 



6 . 



7 • 



8 . 



9 • 



10 . 



11 . 



12 . 



13 • 



14 . 



15 • 



16 . 



17 • 



18 . 



19 . 



20 . 



21 . 



22 . 



23 ■ 



24 . 



25 • 



26 . 



27 . 

 2S . 



29 . 



30 • 



R.A.Cf 



h. m. 



II 43-6 



.So'4 



11 57-2 



12 3-9 

 io'6 



17-3 

 23-9 



30'4 

 36-8 



43 "2 

 49'S 



12 557 



13 I '8 

 7-8 



137 

 19-5 



25'2 



30-8 

 36-3 

 417 

 470 



52-2 



13 S7'3 



14 2-3 



7'i 

 14 11-9 



Ephemeris of Palisa's Comet 



Decl. <# 



••+44 47"o 

 •• 44 158 

 •• 43 427 



43 

 42 

 41 

 41 



7-8 

 3i'> 

 52-5 



I2'I 



40 30-0 



39 46 I 

 39 o'S 

 38 I3'3 

 37 24-5 

 36 34-2 

 35 42-4 

 34 49'2 

 33 54 8 

 32 59 '2 

 32 2-4 



31 



30 

 29 

 28 

 27 

 26 

 25 



4-6 

 5-8 

 6-2 



57 

 47 

 3'o 

 0-8 



47, Brook Street, 



... + 23 58-2 

 September 5 



Log. ^. 



0'22I9 

 •2I9I 

 •2163 

 •2137 

 •2II2 

 ■2088 

 •2065 

 •2043 

 •2023 

 •2004 

 •1987 

 •I97I 

 •1957 

 •194s 

 ■1934 

 •1925 

 •I917 

 •I9II 

 •1907 

 •1905 

 •1904 

 •1906 

 •1909 

 •I9I4 

 •1920 



o'i928 



Log. r. 



0-0393 

 •0362 . 

 •0331 

 ■0301 

 •0272 

 •0243 . 

 •0215 

 •0187 

 •016I 

 •0136 . 

 •01 1 1 



•0087 

 •0064 

 •0042 . 

 •0021 



0"OOOI 



9-9983 



•9965 ■ 

 •9948 

 ■9932 

 ■9919 



•9906 . 



•9895 

 •9885 

 ■9877 



9-9869 . 



Bright- 

 ness. 



■ 17 



rS 



2'i: 



2-S 



2-3 



2-3 



Lindsay 



Insect Swarms 



It may be worth mentioning in connection with Mr. J. Clarke 

 Hawksbaw's interesting account of the wonderful insect-swarm 

 at Trouville, on August 12 and 13, that the two species which 

 composed it were noticed in immense profusion about the same 

 time in the West of England. 



On the 13th ult. (which was one of the very few summer days- 

 of the season) I was driving with a friend from Exmouth to 

 Budleigh-Salterton, on the South Devon coast, when our atten- 

 tion was attracted by the enormous multitude of insects (moths 

 and butterflies) which were fluttering over the flowery margin of 

 the road. The butterfly was at once recognised as the " Painted 

 Lady ; " the moth was not determined, but from its general ap- 

 pearance, its companionship, and all the circumstances of the 

 case, I have no doulit that it was the Pltisia gamma. The swarm 

 attended us, with little variation in the numbers, throughout 

 almost the whole of our journey (a distance of five miles), and 

 on reaching Pudleigh we found V. cardui clustering thickly on 

 the flowers in the brilliant little gardens facing the sea. 



Along the road the moth was in the greatest profusion, the 

 numbers being frequently so great as to form a perfect cloud. 



The effect of the quick, restless, irregular movements of the 

 great host, stretching on mile after mile, was very curious. The 

 butterflies were, of course, less plentiful, but still their numbers 

 must have been immense. They seemed to be finely coloured 

 and in very perfect condition. 



The direction in which the swarm was travelling was not 

 specially noted ; indeed if food was the object sought it might 



