YoL. I. No. 6. 



THE AGRICULTURAL NEW.S. 



89 



slir liad let all till.' glass fall at Baiba^liis and the 

 minerals in the sea.' 



IlKITISH MUSEU.M KEruKT. 



-Mr. (i. T. Prior, M.A., ofthe Miiieralogical Depart- 

 ment of the British Miise\im (Natural History) who 

 also took part in the (liseussion at the (ieological 

 .Society, has forwarded the ioll.iwing ivport to the 

 Department on a sample of the same tlust sent to the 

 Museum : — 



A saini'le of the dust was .sciiarated Ijy means of lieavy 

 liijuid.s into the following threu main eonstitut'nt.s : — 



(1) Light pumiwous grains in coniiiarative small 



amount, ahout 4A per cent. 



(2) (irains of plagioclastie lime-soda felspar and deep 

 brown glass, n:'.irly opicpia owing to magnetite, 

 about 71 per cent. 



(.■^) Heavy grains of magnetite, hyperstLene, augite 

 and a little hornblende, about 24.' [ler cent. 



The mineral constituents of the dust indicate that the 

 eruption i.s of an andesite character, and that in all proljatjil- 

 ity any lavas which may be erai)ted will be found to consist 

 mainly of hypersthene-augite-andesite.s sinular to the jirevail- 

 ing lavas of ile.xico and the Andes. The eruption is thu.s 

 connected with the great American (Pacific) volcanic chain 

 rather than with the .Atlantic. 



An examination of the volcanic dust, of much finer graiii, 

 which fell in liarbados after the eruiition of St. A'inceut in 

 1812 shows that, qualitatively at least, its comi^sition is very 

 similar to that of the present dust. It contains the same 

 constituent.s, viz :— punnceous grains, felspar, felsjiar grains 

 and grains of magnetite, hypersthene and augite. The rela- 

 tive proportions however of the constituents in the two ca.ses 

 are diti'erent. The volcanic dust of KS12 contains compara- 

 tively few of the heavier grains of magnetite and lyroxenes 

 (about 11 i>er cent.) but a larger a)nount of the glassy |iunn- 

 ceous material (about 9J. per cent.) As the dust of 1S12 is .said 

 to have had a remarkably lieneficial effect ujion the crops of 

 the following year in Jiarbados, the general sinnlarity of the 

 present dust with that of IS] 2 would suggest at first that a 

 like effect might be expected next yeai-. The fertilizing 

 properties, howe\'er, jirobably dejiend to a large extent upon 

 the more easily decomposed gla.ssy material containing most 

 of the potash ; the smaller amount of the |iunnceous grains 

 in the i)resent dust therefore rather nnlitates against the 

 idea that this fall of dust will lie to Barliados a lilessing in 

 disguise. 



Chenucal analyses of the dust have already been made 

 and published, one by Dr. Pollard of the Geological Survey 

 (/'roc. (Ir-ol. Soc, May, 1902) and one by Mr. B. E. R. 

 Newlands {Chrinicn/ Xeirs, Vol. S."> (1902), [i. 258). As it is 

 not desirable that one Government Department should 

 duplicate the work of another, 1 have made no chemical 

 analysis my.self but append here the residt obtained by Dr. 

 Pollard. [See iirevious page.] 



If this analy.sis represents the composition of the dust 

 over the greater jiart of the island, the small amount of 

 alkalies and esjiecially of potash supports the above sugges- 

 tion that the iiresent dust will be of less benefit as a 

 fertilizing agent than that of 1812. 



RE1>()11T F)l<)M THE GOVERX.MEXT LAliOKATi )11Y ];1;IT1SI1 

 GUI.\X.\. 



Through the courte.sy of the Government of 

 British Guiana, the Dejjartment has received the 

 following report by Prof J. B. Harrison, CUr.(i.,]M.A., 

 F.G.S.,F.C.S., on a samjile of the dust which fell at 



B.ubados on May 7-S: 



Dr. Morris' sample was collected by the Conuuissioncr 

 jiersonally on a sheet sjiread on the lawn of his residence, 

 and hence is free from impurities. The analysis of this 

 samjile by Mr. W. L. F. Kaufmaim, the Assistant Analyst, 

 has given the following results : — 



D I sf.oI vrij hij HoUihh ill 



hhiliiig 11 ijihiy- 1 per vent. so/t(- 



chlouc acid. ti'jii Citric fiA- ill. 



Moistiu-e -180 



Loss on ignition * ... 440 



Silica .j1-7C0 



Titanium oxide ... 2778 



Alumina :i2G79 7 74 5 -(j'yl 



Mangane.se peroxide 081 

 Iron jieroxide ... 3290 "\ (.i-n 

 Iron jirotoxide ... 1760 J 

 Calcium oxide ... 9440 4779 



Magnesium oxide ... 42.iO "871 



Sodium oxide ... 2-."j00 1-782 



Potassium oxide ... ■4.")8 070 



Phosphoric anhydride 111 '044 



Sulphuric auj'lidride '007 '007 



Suljihur in sulphides 007 

 Ilaiium oxide ... •1.'.52 



Lead traces 



Clipper nil 



Nickel traces 



•4U0 



•397 

 •214 

 •003 

 ■004 

 •019 



99-913 19^834 



P6S9 



■01 



■* Including nitrogen. 



The constituents rendered soluble by prolonged lioiling 

 in 20 jier cent, hydrochloric acid may be taken a.s repre- 

 .senting the constituents of the .saiidy ashe.s which may be 

 converted into soil constituents or removed therefrom in the 

 course of years. 



The readily available constituents of plant food present 

 in the sanijile are determined by digestion, in the cold, with 

 1 per cent, citric acid for five days. These figures [the third 

 colunni in the above table] conclusively .show that this 

 volcanic dust is cpute \aluele.ss as a manure, the value of 

 its soluble constituents being about three cents. 



For other analyses see ])ag-es 44, aiKJ 73. 



Curing an Egg-Eating Dog. 



The Qtieenddnd A(/ricidtiinil Joanxil suggests 

 the following cure for this troublesome habit : — 



Many and various have been the reciiies given as a 

 certain cure for a dog gifted with egg-eating }iropensitics, 

 but we can recall but one remedy which has proved eti'eclual — 

 a shot gun. A new idea however has struck some one with 

 a chemical turn of mind. Possessed of a dog, one probably 

 too valuable to destroy, which was in the habit of hunting for 

 hens' nests and making a clean sweep of the whole contents, he 

 tried a new plan. He blew an egg and filled it with strong 

 si>irits of ammonia, carefully plugging the appertures. This 

 egg he placed among others in a nest well known to the dog-, 

 an(l awaited develojiments. In due time the egg-e;iter dis- 

 covered the prize and proceeded to business, but when he 

 crunched up that egg he sneezed, conglied, gasped fen- lireath, 

 fell down and writhed several times, and at la-st, when lie had 

 after ten minutes sufficiently recovered to proclaim his 

 unutteral)le Iiliss, he fled and would never, afterwards, look at; 

 an egg. This is a simple remedy worth trying. 



