July 28, 1882.] 



♦ KNOWLEDGE ♦ 



149 



siderable pest, while innumerable noxious species hare crossed the 

 Atlantic from Europe. There is a comparative scarcitv, too, cf 

 Asiatic insect species on the western seaboard of America,' notwith- 

 standing frequent ocean traffic. Spite of great arid plains and lofty 

 mountains, nearly all the insects of Eastern American States, 

 including those from Europe, have found their way across the con- 

 tinent to the fields, orchards, and vineyards of the Pacific States. 



A Fkee Postal PnoxoGBAPnicAL Society has been founded as a 

 postal society for the convenience of amateurs in different parts of 

 the country for (1) the circulation of prints, negatives, Ac, (2) the 

 exchange of [.hotographs and of information on photographic mat- 

 ters, and for the general advancement of the science and art of 

 photography. This society will in no wav interfere with any society 

 now in existence, but will rather tend to the advancement of 

 existing societies by bringing their members more into communication 

 with each other. Entrance fee, 2s. 6d. annual subscription, 5s. 

 Further information and a copy ef the rules may be had on appli- 

 cation to H. H. Cunningham, Hon. Sec, 7, Fig-tree Court, Temple. 

 Tbebe is a weed in the South known as the wild coffee plant, 

 which has caused the planters a good deal of trouble and annoyance, 

 and has consequently been greatly despised. It has recently been 

 discovered that the plant has its use, as rope can be made from it 

 equal to the best hemp, and stronger and finer than jute. The dis- 

 covery was made by a negro who needed a piece of rope, but could 

 find none. On looking around, his attention was attracted to this 

 plant, and he cut the stalks and treated them in the same manner 

 he had been accustomed to see hemp treated in Kentuckv, and the 

 result was a fibre of good length and of surprising strength, which 

 the old man soon converted into rope. 



Tholght Beading.— a Plymouth correspondent (notes the E,ho) 

 says a strange incident is reported in that town. On Tuesdav 

 evenmg a young man, residing at Devonport, called upon the Editor 

 of a local paper and begged to be informed if any telegrams had 

 l>een received giving the names of Englishmen killed during the 

 day in Alexandria. He was informed that no such message had 

 been received. He thereupon mentioned that during the afternoon 

 the mother and wife of a petty officer named Revington, servin<' in 

 Alexandria, had what they regarded as a token of his death. They 

 were sitting together in their house, talking and working-, when they 

 heard, or thought they heard, the voice of the absent eon and 

 liusband say, " Mother 1 " three times. With forebodings upon them, 

 the brother ^vas at once despatched to the nearest newspaper office, 

 with the result indicated. On Wednesdav, however, the relatives 

 of Mr. ReviEgton received a telegram from the Admiralty to the 

 cITcct that he was shot in the streets of Alexandria on Tuesdav, 

 whilst sen-ing on police duty. 



The Salt L.ike (Utah) Herald says that sea gulls have been un- 

 commonly numerous and active there this spring. Wherever there 

 was a newly-ploughed field, there vou could see the gull, and as 

 fast as a furrow was turned up the birds would fly behind the 

 ploughman and commence devouring the insects which were thus 

 exposed to sight. They seemed perfectly fearless. And they have 

 grod reason to be fearless here, for the farmer looks upon them as 

 his rriencl, and they seem to understand fully that he holds them in 

 that light. They rty all about him, within three or four feet, and 

 while perhaps unwilling to submit to being caught, they will allow 

 any other familiarity that can bo practised, for they themselves 

 take a great many good-natured liberties. They will not touch 

 trrain.or anything that the farmer desires should remain untouched ; 

 th.y only eat the worms and insects which are injurious to tke soil 

 n, to crops. Only once before have the gulls been so numerons, 

 : .1 that was in ISks, when they sived the settlers from an invasion 

 ' 1 mountain crickets. 



^^ 



Ittttvi to tt)t eiittjjr. 



[The Editor doet not hold )i 

 He cannot undertulce to retut 

 communieationt thould be m 

 mente of the trriler'e meanini) 



All Editorial commuHiattii 

 all Buiinee, » 



All Uemittiitcet, Clieqv.e; an 

 Meura. Xi\man tf So'l. 



•»• All letlere to the EdUor 

 corretpondentt, vhen re/erriwi t 

 and the page on Khich it appear*. 



>elfre,pon,Mefor the opinion, of hie corre.pondeut.. 

 maautcnpttoT to corretpond riti their xritert. Alt 

 \ort ae poeeMe, coneietenlty rith/uU and clear etate- 



,.hoM I, adJre„ed to <h. Editor of KlfOwllDCE : 

 to the rnblt.her,, at the Office, 74, Great queen. 



nd Poet-Office Order, ehould U made pagaile to 



•ill le XumhrreJ. For < 



, rill oblige by mentioning it, number 



y is to be contemned and despised who is not in ■ 

 >or u there anything more advene to accuracy 



AMEBIC.4.N Watciies i.s Xew Zealaxd.-Iu a report On the watch 

 and clwk trade of New Zealand, Consul Griffin (American) savs 

 that, though the introduction of American clocks and watches into 

 -Now /calaiid is comparatively of recent date, they have become so 

 very popular and so general in use that the trade in them bids fair 

 to swell to largo proportions. Most of these goods reach Now 

 Zealand by way of London. Mr. Bartlett, a leading jeweller of 

 Quoen-street, Auckland, said to Mr. Griffin : " It is difficult to sell 

 an English watch, and as far as the Geneva watches are concerned, 

 they are l«ing fast driv.n from the market. Everybody seems to 

 want an American watch. I am not preparo<l to say that American 

 watches are any better than other watches, bnt it is the fashion to 

 to liuve them. There is not a boy or a servant girl in the country 

 who can raise five pound.q, who does not want to invest it in an 

 .\mencaii watch." Mr. Bartlett, while acknowlclging t ho popularity 

 of American watches, expresses a decided preference for the old- 

 fashioned hand-mado waU-h, but frankly admits that his customers 

 do not agroo with him. 



" In knowledge, that man 

 itate of transition. , , . 

 than fllitT of opinion."— Furarfuy 



do'^e norhSg."!:^-,!-; ""^" °° "'"'''"■ ""* ' "'" "'"^ ^"" ' "^ '"'° *■" 

 AN EFFECTIVE ACCCMCLATOR. 



[485]— Some time since you published in Knowledge a description 

 of Sutton s accumulator. A scientific friend, Mr. J. Williams Gifford 

 of Chard, informs me that he has obtained much better results 

 with an accumulator of which I append a description. 



The accumulator consists of a lead trengh, coated on the inside 

 with finely divided lead. This is formed from red lead laid on and 

 retained in its place by a lining of canvas, kept close to the sides 

 of the box by wooden stays. In the middle of the lead box is 

 suspended a plate of zinc well amalgamated. It is weU thoroughly 

 to amalgamate the lead before laying on the minium, so as to form 

 a thoroughly good connection between the lead and the finely 

 divided lead formed from the minium. 



To form the cells, they are filled with sulphuric acid and wafer, 

 one of acid to nine of water, and are connected in series ; the zinc 

 is thus dissolved by the acid, which changes to a zinc sulphate solu- 

 tion, while the lead oxide becomes the before-mentioned finely 

 divided lead. The cells are now ready for use. It is to be distinctly 

 understood that no external batterj- is to be used to form the cells - 

 their own current is quite sufficient. When formed, they may bo' 

 charged by a dynamo or battery, but require a motive force of from 

 5 to 6 volts for each accumulator. 



It is well to keep the zinc thoroughly amalgamated ; this will 



ensure the maximum of current : 



I out after a given charge. If 



the accumulator is only required to last from half" to one hour the 

 minium may be omitted with advantage, and the lead only 

 amalgamated, but if for several hours it must bo used, but will 

 slightly increase the internal resistance. Tho sulphate of zinc 

 solution made in forming the cell gives up its zinc, which is electro- 

 plated on the large suspended zinc ; the finely divided lead is 

 changed into lead peroxide by tho atoms of from the H.O split 

 up during action, while the H escapes as bubbles ; (hence it is 

 necessary to add a little wafer from time to time) the solution lelt 

 when fully charged being UjSOj -I- 1I..O. John Beowmvg 



PROGENITOR OF VERTEBRATA. 

 [iSG]— "W. R." puts a highly interesting question to me. 

 requesting information regarding a statement made bv me in an 

 article in Good 11 n,d^ for lt.75, wherein 1 .«ay that from personal 

 observation I believed tho notochord of tho Ascidian larva to be 

 ' ventral" in position. I need not sav to those readers of 

 Knowleiige who have perused my pnpe"r.s on •• Found Links." 

 that if I still ninintaiued this view, the homology or rela- 

 tionship (maintained by evolutionists) of tho ."sea-s.iuirt larva's 

 •notochord" with that of the lancolet could no longer bo 

 urged by mo. The correspondence of the two structures in so*- 

 sqnirt and lancelet respectively depends on tho recognition 

 of tho fact that they nro cxactiv and hereditarily related. Tho 

 notochord is tho enmo in both ; it is dorsal (or lie.s in the back) 

 m both sea-sipiirtand vertebrate— such is the evolutionist's strong- 

 hold. Now, since 1N75, every naturalist has learnt a vast deal 

 respecfing "sea-squirt " development and vortcbrato homologies. I 

 have groat pleasure in fully and freolv acknowledging that, 

 although, whilst fairly stating tho t«o views hoM on tho subject 

 "'j''"5'. »'"1 whilst leaning to the si.lo of Von Barr. Mecznikow, 

 and others, I have since fouud reason to change my opinions, ana 



