470 



KNOWLEDGE • 



[Dec. 



St Louis. From him I learned that, when I don't know 

 a thing, I say that I don't know it ; and tliat, when I do 

 know a thing. I speak !is if I were quite certiiin about it 

 To the interviewer, as 1 gatliered from his report, this way 

 of acting seemed a little strange, tliough ho clearly approved 

 of the tvcentricity. To luy own mind, the puzzle would he 

 why any man should eitlxr pretend to know a thing which 

 he does' not know, or pretend not to know a thing which 

 he docs know." 



In- the Z'ilschriji fiir Anahilisch' Chcmie, Tjadon Mod- 

 dermann remarks that he has for some tin\(> been accustomed 

 to prepare pure sulphuric acid by recrystallisation of the 

 hydrate (H.SO.II.O), and finds this seldom-adopted method 

 of purification to l>e really an excellent one. The author 

 has e.xperimented in this way upon acids containing con- 

 siderable quantities of lead and arsenious and nitric acids, 

 Ac, and by protracted recrystallisation has in all cases ob- 

 tained a pure acid from them. The method is very simple. 

 The acid is mixed with sutlicient water, and, in bottles two- 

 thirds full, exposed to the cold in the open air on a frosty 

 night If the mi.xture has been properly made, it is gene- 

 rally frozen throughout the ne.xt morning. The chief thing 

 then is to carefully separate the crystals from the mother 

 liquor, and for this purpose the author employs a centrifu- 

 gal apparatus, so constructed that the acid only conies in 

 contact with glass. The separation is very easily ellected, 

 and, except incases where an acid is strongly contaminated 

 with the different oxides of nitrogen, one recrystallisation 

 is generally sufficient 



AccoRDiXf, to stitistics compiled by the Agricultural 

 Bureau, at Washington, the annual meat product of the 

 United States is in round numbers : — 



Nambcr. Poand«. 



Dressed hog8 29,000,000 5,120,000,000 



BccTcs 6,250,000 3,121,000,000 



Veals 3,000,000 275,0(X),000 



Mattons 7,000,000 350,000,000 



Lambs 5,000,000 100,000,000 



Alx)ut one-fourth of the pork and one-twelfth of the beef 

 are exported, leaving for homo consumption about seven 

 thousand six hundred and fifty million pounds of the above 

 raeats, mostly beef and pork ; or an average of almost half 

 a pound a day for every man, woman, and child in the 

 country. 



At a meeting of the Manchester Geological Society, Mr. 

 C. E. De Ranee, of the Geological Survey, read an 

 interesting communication with reference to an important 

 discovery of manganese ore near AVjorgeie, in Denbigh- 

 shire, occurring in the old red sandstone. The depo.sit, 

 lie explainf^l, occurred in a bed, and not in a vein, as in 

 the ordinary way, and reached a thickness of 17 ft of solid 

 ore. The <\ti>omt had l»een opened out by the Atwrgelo 

 Hematit<- (>)mpany, and its existence had previously lioen 

 •o little 8usp«-ct'-<l, that the ore had actually been used for 

 paving purf>o»eg. Ho was of opinion that close investiga- 

 tion of similar localitien throughout North Wales would 

 leiul to the discovery of other deposits of like nature, 

 which would Yd: of great value, considering the present 

 deman'l for mangan'-s^; for the manufacture of Ilessemer 

 rt/-*! \iy the Spi'g<-leis<;n process. The source of this ore, 

 he was of opinion, was the basement >K;d8 them8«!lves, the 

 metal l«ing concentrated V>y the percolation of water down- 

 ward*, until arrtisted by the impermeable floor beneath. 



TiiR Captain-General of the Philippine Islands telegraphs 

 from Manilla that on tlio first day after the recent hurri- 

 cane, which almost entirely destroyed the town, not a 

 single case of cholera occurred in ]\lanilla or the island. 

 The tornado not only swept over the entire archipelago, 

 but was felt many hundred miles out at soa, especially to 

 the south and west It is believed that more lives have 

 been lost by shipwreck than on land. 



They have a curious way of clearing away wrecks in 

 Ireland. Recently an attempt was made to blow up the 

 steamship SUkstoui\ which had sunk in the Suir, opposite 

 Waterford Quay. The force of the explosion was so great 

 that the windows in every house on the quay, the principal 

 street in the city, were smashed to pii'cos, and goods and 

 articles of furniture dashed about the shops and houses in 

 every direction. So great was the amount of damage dope, 

 that the shutters were put up in every shop. Nor did the 

 windows in the upper stories escape. Several shop as- 

 sistants were knocked ofl" their legs. A Times correspon- 

 dent says the principal Viusinoss concerns of the city have 

 been completely wrecked, but leaves it to be inferred that 

 the " .S'j7/i>tonc " remained monolithic. 



M. Dumas recommends water saturated with alum for 

 extinguishing fires, its value being supposed to be duo to 

 the coating it gives to objects wet with it, which prevents 

 contact with the oxygen of the air, and thus diminishes the 

 rapidity of the combustion. The Minister of the Interior 

 has recommended that the firemen of the Fi-ench towns 

 be supplied with facilities to use such solutions of alum. 



An automatic electrical appliance for giving notice of 

 the approach of trains, invented by M. Mors, has, says 

 the Ex'jiiii^cr, been successfully tried on the Paris-Lyon- 

 Mediterrance line. It consists of a box filled with 

 mercury placed under the rail at the required distance 

 from a bell ; the trepidation caused by a train passing 

 over it agitates the mercury, and forms contact with the 

 wire communicating with the bell, thus causing it to ring. 



A Broker's office in Wall-street, New York, having a 

 leased wire, sent up a message to 195 on the morning of 

 the big electrical storm to know what was the matter 

 with their wire. Chief Operator Bogart replifid that the 

 " aurora " was on it The firm thiToupon telegraphed 

 back to have it cleared ofl' immediately, as they wanted to 

 use the wire. — Operator. 



Di/'itixo the discussion at a recent special meeting of 

 the Town Council of Newcastle-on-Tyne, one of the speakers 

 said that Liverpool liad spent £15,000 on electric lighting 

 experiments, and then rejected a proposal to apply to 

 the Board of Trade for a provisional order. 



At a meeting in New York, on Nov. 21, of tho share- 

 holders of the Edison Company for Isolated Lighting, a 

 report was re^d of tho business done by the Company 

 during tho year ending Nov. 19. In this period, 1.37 in- 

 stallations had been fixed, the total number of lamps in 

 use l)eing 25,751. A dividend at the rate of 11 per cent, 

 per annum was declared. 



There is a charming article about cricket in Loni/man's 

 Mtujazine for January. It is from tho pen of Mr. 

 Murdoch, the captain of the Australian eleven. 



