68 



MEETING OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 



[1853 



of tlie solar rays increased. The results, however, which he has ob- 

 tained during the brief sunshine of the present summer, leads him to 

 hold that opinion in suspensi u. In many of the spectra obtained 

 (copies of which will be appended to the printed report) there appeals 

 to be evidence of the conversion of one form of force into another — the 

 change indeed of light into action or chemical p wer ; and, again, as in 

 Mr. htukes' experiments the exhibition of the ordinarily invisible che- 

 mical ia,s in the form of light. 



Prof. Stokes off red some remarks upon the different effects pro- 

 duced by the spectrum, dividing them into luminous effect, chemical 

 action, cal irilic power, phosphorescence, and fluorescence. '1 hese were 

 different effects resulting from the same cause and he did not consider 

 that sufficient evidence had yet bee given to warrant the idea that 

 there existed any dissimilar agencies in the solar rays. 



Prof. Johnston, the Rev V. Harconrt, Dr. Daubeny, Mr. Claudet, and 

 others, took pait in the conversation which followed. 



'On the Employment of the higher sulphides of Calcium as a means of 

 Preventing and Destroying the Uidium Tuckeri, or Grape Disease' by 

 Uit. AstlkY P. I'kick— Of the many substances which have been em- 

 ploye to arrest the devastating effects of this disease, none appear to 

 have been so preeminently successful as sulphur, whether employed 

 in the state of powder or flowers of sulphui, or by sublimation in houses 

 so affected. Notwithstanding the several methods described for its 

 application to the vines, 1 am not aware that auy had been offered in 

 1851, when these experiments were instituted, by which sulphur might 

 be uniformly distributed over the branches, and be there deposited in 

 such a manner as to be to some extent firmly attached to the vine. 

 Three houses at Margate, iu the vicinity of the one in which the 

 disease first made its appearance in England, having been for the space 

 of five years infected with the disease, and notwithstanding the em- 

 ployment of sulphur as powdered and flowers of sulphur, no abate- 

 ment in its ravages could be discovered,— I was induced to employ 

 a solution of peutasulphide of calcium, a solution of which having been 

 found to act in no way injuriously to the young and delicate shoots of 

 plants, was applied to the juices in a dilute couditi n ; the obj ct in 

 view being that, the compound should be decomposed by carbouic 

 acid, aud that ihe excess of sulphur should be deposited with the car- 

 bonate of lime iu a uniform and durable covering 'on the stems and 

 branches of vines. This was adopted, aud alth nigh but few applica- 

 tions were made, the stems became coated with a deposit of sulphur, 

 aud the disease gradually but effectually diminished, in so much that 

 the houses are now entirely free from any trace of disease or symptoms 

 of infection. The youug shoots are in no way injured by its application, 

 and the older wood covered with this deposit of sulphur continues ex- 

 ceedingly healthy. This was, we believe, the first employment of the 

 higher sulphides of calcium as a vehicle lor the application of sulphur 

 to the siems and foliage of the diseased vines. Specimens were exhi- 

 bited from vines which in 1851 were covered with disease, and which 

 have since the autumn of that year received no fuither treatmeut. The 

 vines iu the immediate neighbourhood, and adjoining one of the houses, 

 are covered with disease, but, notwithstanding their close proximity, 

 no indication of the disease has at present beeudetected iu either of 

 the three houses. 



' On ihe effect of Sulphate of Lime upon Vegetable Substances,' by Cheva- 

 lier Clai'sskx. — About six weeks since 1 was engaged in making 

 various experiments on the effect of Sulphate of lime upon vegetable 

 substances. A portion of the substances then used by me was thrown 

 carelessly aside, aud upon returning to my experiments about a fort- 

 night afterwards, I was surprised that the decomposition had not 

 taken place iu those portions of the vegetables which had been sub- 

 jected to the action of the sulphate, while those which had uot been 

 so treated wtre completely decayed Amoug the articles experiment- 

 ed upon were a number of potatoes, each of which was affected by 

 the prevalent disease; some of these rema n sound to the present day, 

 the others have some timesince completely rotted away. Subsequently 

 I procured some more potatoes, aud also some beet-roots, the former 

 being, as far as I could judge, all diseased. I divided the potatoes 

 into three portions. One lot I placed iu a vessel with a weak solution 

 of sulphuric acid, aud from thence I placed them in a solution of weak 

 lime-water. In the second lot the process was reversed, that is to say 

 the potatoes were first placed in the lime-water, and then iu the acid. 

 The third lot was left untouched. Ten days afterwards I examined 

 the potatoes; those whichhad not been treated with the sulphate were 

 rapidly decaying, — those which had beeu first placed iu the solution of 

 lime aud then in the acid were more nearly decomposed, — while those 

 which had been treated in the mode first described remained as 

 sound as wheu first taken in haud. Upon being cut open the diseased 

 part of the potatoes was found to have spread internally, and the fla- 

 vour of root was in no degree affected by the application of the process 



nor do I think that its germinating power was injured by the effect of 

 the sulphate. I he effects upon the beet roots was similar to that pro- 

 duced upon the potato, and which wo Id seem to be somewhat 

 aualagous to that of galaniziug metals, viz : protecting the substances 

 from the effect of atmospheric agencies. I may add, that muriatic and 

 other acids have been employed by me on other occasions with equal 

 success, the only agents required appealing o be tho e which will 

 most readily produce a sulphate in contact with the sutstanccs requir- 

 ed to be preserved. As at present it di < ■> m t ap] ear that any means 

 can be successfully adopted to prevent the potato fiom beci mine dis- 

 eased while in the ground aud arriving at maturity, it would cer- 

 tainly be of immense advantage if anything could be dbcevcied by 

 the use of which the roots when taken up Could be pievented from 

 that absolute decay aud irreparable loss to v hii li | otati es affected by 

 the disease are liable. The results which 1 have described seem to 

 me to point to the possibility of arresting this loss. How far the plan 

 suggested may be practicable or applicable upon a large scale, my 

 present very pressing and numerous engagements have hitherto pre- 

 vented me from ascertaining. 1 do not think that any msu] erable dif- 

 ficulty exists with lespect to the application of the process- 'Ihe 

 acid employed by me was very weak, about one part to two hundred 

 of water; the lime water was about the consistency of milk. '1 he ma- 

 terials are not, therefore, expensive: and when the value of the crop to 

 be saved is taken into consideration, it would be a matter well worthy 

 of being tested by some of those extensive growe 's of potatoes in the 

 county iu which the British Association is now holding its sittings. 

 For my own part, 1 should be most happy if any sug i -lion of mine 

 had merely beeu the instrument of diiectingthe attention of scientific 

 men to the subject of the possibility of preserving from total destruc- 

 tion a vegetable so valuable aud so indispensable as the potato. 



' The results of the Census of Great Britain in 1851, uitli a descrip- 

 tion of the machinery and processes employed to obtain tin 1 Returns.' by 

 E. Cheshire. — 'Ihe author commenced byreciling the onerous duties 

 of Registrar General. The objects of the census we e expla lued, aud 

 the machinery employed to take it Great Britain was appoitioued 

 into 38,740 enumeration districts, and to each of them a duly qualified 

 enumerator was appointed. The author illustrated the extent of this 

 army of enumerates, and the labour of engaging their services on the 

 same day, by staling iliat it would lake i3)i hours to Count them, at 

 the rate of one a second, and thai the auny recently cmcampid at 

 Chnhham would not have suffered to enun erate a foi rth of the pi pa- 

 latum of Great Britain. '1 he bound iries of t' e enumeration districts, 

 and the duties of ihe enumerators, were di fined, 'lie run 1 ei of 

 householders schedules forwarded from the Census Ofl'ne was 7 000- 

 O'lO, weighing 40 tons. The pmci sses employed to ei umeiate persons 

 sleeping in burns, tents and the open air, anil in ksh!s, were si verally 

 explained; also the means by which the numbers of British subjects 

 in foreign Slates were obtained. Tl epieciiutious taken to ecnie ac- 

 curate returns were recited; they involved the final process of a minute 

 examination and totalling, at the Census Office, of 20 millions of 

 entries, contained on upwards of lj„j millioi s of pi-ges ol ihe enume- 

 rators' books. The latfe-i were upwauls of 38,001) iu number. The 

 boundaries of the fourteen registration divisions were traced, and the 

 plan of publication of the census was explained. Tl e number of 

 persons absHtil from Great Britain on the nigl t of ihe 30 h of March, 

 was nearly 200.000: — viz army, navy, and merchant sen ice, lO^^O; 

 and British suljects resident and travelling in foreign countries, 33.775. 

 The various cau-es of displacements of ihe population were leciled; 

 and the general movement of the population on tin- occasion if ihe 

 Great Exhibition was alluded to.t The number of visits 10 the Cm s- 

 tal Pal ice were 6,039, 19 •; aud the number of people who visited it 

 was 2,000,000, nevertheless the landing of only 65 233 aliens were 

 report d in the year. The population of Great Britain inl85l is sub- 





Males. 



• 



1- finales. 



Total 





8 281.734 



1,375 479 



499,491 



66,854 



162,490 



8 64H.I54 



1513.263 



506,230 



76,272 



10.921 >88 





2.888.742 



Wales 



1,0115 721 



Islands 



Army. Navy and Mer- ) 

 chant Service. $ 



143,126 



162.490 



Tntal 



10386048 ' 10.735919 



-1,1 <ll Q07 



I'll celiMU Ullislrale.i (Ills 21,000.0 tl -1 , epic ny a., anw lu 



the Great Exhibition. On one or two occasions lOd.Ol'O visited the 

 Crystal Palace in a single day, consequently 21 1 days of sucn a Jivii g 

 stieam would represent Tie number of tie Biitish ] 1 1 ulation. 

 Another way of realizing 21,000 000 of people was arrived at by cn . 

 sideling their numbers iu relation to space; allowing a square ya 



