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Acetylene
76
Notes and Comments.
[ J . F. I.,
precipitable. From glucinium, lucium differs, as its s a l t s are precipitable by oxalic acid. T h e lines in the spectrum of lucium are special, a n d only approximate slightly to those of e r b i u m . E r b i u m oxide, on ignition, appears of a very pure rose-color, a n d its nitrate is red. On the contrary, lucium oxide is white, slightly grayish, a n d its nitrate is white. T h e aqueous solutions of the erbium salts are red or rose-color ; those of lucium, e v e n if containing 15 or 20 per cent. of the salt, are almost colorless. T h e s e a n d other reasons seem to show that lucium is a new distinct e l e m e n t a r y body. Its atomic weight h a s b e e n calculated as = Io4. PRODUCTION OF AMBER. T h e working of a m b e r in Prussia is a m o n o p o l y in the h a n d s of a firm which owns the best two mines, P a l m n i c k e n a n d Kraxtepelle. For the concession the firm, according to Consul H u n t , of Dantzig, pays to the G e r m a n G o v e r n m e n t a royalty of 65%o0o m a r k s (.about $x62,ooo) a year. It is r e c k o n e d that this firm h a s up to now paid no less a sum t h a n $5,ooo,ooo in royalties to the G e r m a n G o v e r n m e n t . In addition to t h e output from the mines in 1895, a good deal of a m b e r was picked up on the b e a c h at Pillau, in t h e p r o v i n c e of E a s t Prussia, b e i n g w a s h e d up with the seaweed d u r i n g the p r e v a l e n c e of northwesterly gales. T h e shore at Pillau after a storm is sometimes covered with a layer of s e a w e e d 3 feet thick, a m o n g which t h e a m b e r is found entangled. Men, w o m e n a n d children find easy a n d lucrative e m p l o y m e n t in s e a r c h i n g for the a m b e r a l o n g this part of the a m b e r coast. T h e people e n g a g e d in this precarious work often earn 3° shillings a d a y a n d more. In I895, about Ioo tons of raw a m b e r c a m e to D a n t zig to be w o r k e d up, as c o m p a r e d with x4o tons in x894. It was n e a r l y all m e l t e d to m a k e lac a n d v a r n i s h . T h e larger pieces are m a d e into beads, which are sent all over the world. T h e b e a d s k n o w n to the t r a d e as Legh o r n corals were in strong demand.--Scienti~fc American. ACETYLENE. F r o m the Progressive Age, we take the following d a t a b e a r i n g on t h e behavior of acetylene, which are credited to the investigations of M. B r e v a n s : " I f o r d i n a r y acetylene from carbide be passed t h r o u g h a series of three washing-flasks c o n t a i n i n g a solution of s u l p h a t e of copper, t h e r e is no effect perceptible within t h r e e hours ; but after twelve h o u r s the first flask contains a black-brown, brilliant precipitate, the quantity of which goes on increasing for as m u c h as eight days. This precipitate explodes on shock, friction or heating ; a n d it appears to b e a mixture of p h o s p h i d e a n d silicide of copper, of sulphate of cupro-acetyle, a n d a variable quantity of acetylide of copper. Its production appears to d e p e n d largely on the p r e s e n c e of a m m o n i a in the crude acetylene g a s ; a n d it shows that the crude acetylene c o n t a i n s phosphoreted h y d r o g e n a n d siliciureted h y d r o g e n . T h e second flask contains a precipitate which is similar in a p p e a r a n c e , but less explosive; a n d the pre, cipitate in the third flask is not explosive. T h e explosive precipitate in the
Jan., 1897. ]
Book ~'otzccs.
77
first flask will explode e v e n u n d e r water, as, for example, when we try to rub it off the glass with a glass rod. "As to the explosibility of acetylene there are two opinions: one, that there may be metallic acetylides formed, which act as detonators to the acetylene itself, so that acetylene c a n n o t be used with reservoirs which are capable of b e i n g attacked by it; the other, t h a t it can only be exploded when mixed with air, a n d that the influence of the outside explosions which can set it off c a n n o t travel far through air. In a n y case, acetylene, at a pressure not much exceeding that of the atmosphere, is not explosive, though it is explosive at pressures a b o v e 2 a t m o s p h e r e s ; so that there is no reason to fear an explosion t h r o u g h flame r u n n i n g back to a reservoir u n d e r a very small excess of pressure. Shock alone does not a p p e a r to cause explosion of the gas, only of the acetylides. T h e alleged poisonousness of a c e t y l e n e - - w h i c h has not, as yet, given rise to a n y a c c i d e n t - - w o u l d a p p e a r to be due to the occasional presence of cyanogen compounds, a n d is not a feature of pure acetylene. T h e presence of sulphureted h y d r o g e n in acetylene seems to depend on that of sulphide of a l u m i n u m in the carbide of calcium ; sulphide of calcium m a y exist in it without forming this impurity. T h e b l o c k i n g of gas jets by acetylene flames seems to be due to the formation of phosphoric acid. If oxygen be not present, acetylene does not attack copper ; the oxide must be formed before the acetylide can be produced." ENGINEERING
NOTES.
A m e a n s for ~breventing t~e noise made by trains in passing over iron bridges has b e e n devised by a G e r m a n e n g i n e e r n a m e d Boedecker. He puts a decking of I ~ - i n c h p l a n k s between the cross girders, resting on 3-inch timbers laid on the bottom flanges. On the p l a n k s a double layer of felt is laid, which is fixed to the vertical web of the cross girder. At the connections with the girder a timber cover joint is placed on felt, a n d two hooked bolts connect the whole firmly to the bottom flange. " Four inches of slag gravel cover the decking,which is inclined toward the center of the bridge for d r a i n a g e purposes. A layer of felt is laid between the p l a n k s a n d the timbers they rest upon, a n d the iron work in contact with d e c k i n g a n d ballast is asphalted. T h e decking weighs 60o pounds per yard for a bridge I I feet wide, a n d costs 23 cents a square foot. It is water-tight, a n d h a s proved very satisfactory in p r e v e n t i n g noise.
BOOK
NOTICES.
Tables Showinff Loss of Head Due to Friction of Water in /:'t~es.
By Edm u n d B. Weston, C.E., M e m b e r of the A m e r i c a n Society of Civil Engineers, M e m b e r of the Institution of Civil E n g i n e e r s of Great Britain. New York : D. Van N o s t r a n d C o m p a n y , 23 Murray a n d 27 W a r r e n Street. 1896. Price, $L5 o. T h e author here presents two tables of flow in pipes, one referring to pipes with very smooth i n n e r walls, such as lead a n d brass pipes, from % inch
Notes and Comments.
[ J . F. I.,
precipitable. From glucinium, lucium differs, as its s a l t s are precipitable by oxalic acid. T h e lines in the spectrum of lucium are special, a n d only approximate slightly to those of e r b i u m . E r b i u m oxide, on ignition, appears of a very pure rose-color, a n d its nitrate is red. On the contrary, lucium oxide is white, slightly grayish, a n d its nitrate is white. T h e aqueous solutions of the erbium salts are red or rose-color ; those of lucium, e v e n if containing 15 or 20 per cent. of the salt, are almost colorless. T h e s e a n d other reasons seem to show that lucium is a new distinct e l e m e n t a r y body. Its atomic weight h a s b e e n calculated as = Io4. PRODUCTION OF AMBER. T h e working of a m b e r in Prussia is a m o n o p o l y in the h a n d s of a firm which owns the best two mines, P a l m n i c k e n a n d Kraxtepelle. For the concession the firm, according to Consul H u n t , of Dantzig, pays to the G e r m a n G o v e r n m e n t a royalty of 65%o0o m a r k s (.about $x62,ooo) a year. It is r e c k o n e d that this firm h a s up to now paid no less a sum t h a n $5,ooo,ooo in royalties to the G e r m a n G o v e r n m e n t . In addition to t h e output from the mines in 1895, a good deal of a m b e r was picked up on the b e a c h at Pillau, in t h e p r o v i n c e of E a s t Prussia, b e i n g w a s h e d up with the seaweed d u r i n g the p r e v a l e n c e of northwesterly gales. T h e shore at Pillau after a storm is sometimes covered with a layer of s e a w e e d 3 feet thick, a m o n g which t h e a m b e r is found entangled. Men, w o m e n a n d children find easy a n d lucrative e m p l o y m e n t in s e a r c h i n g for the a m b e r a l o n g this part of the a m b e r coast. T h e people e n g a g e d in this precarious work often earn 3° shillings a d a y a n d more. In I895, about Ioo tons of raw a m b e r c a m e to D a n t zig to be w o r k e d up, as c o m p a r e d with x4o tons in x894. It was n e a r l y all m e l t e d to m a k e lac a n d v a r n i s h . T h e larger pieces are m a d e into beads, which are sent all over the world. T h e b e a d s k n o w n to the t r a d e as Legh o r n corals were in strong demand.--Scienti~fc American. ACETYLENE. F r o m the Progressive Age, we take the following d a t a b e a r i n g on t h e behavior of acetylene, which are credited to the investigations of M. B r e v a n s : " I f o r d i n a r y acetylene from carbide be passed t h r o u g h a series of three washing-flasks c o n t a i n i n g a solution of s u l p h a t e of copper, t h e r e is no effect perceptible within t h r e e hours ; but after twelve h o u r s the first flask contains a black-brown, brilliant precipitate, the quantity of which goes on increasing for as m u c h as eight days. This precipitate explodes on shock, friction or heating ; a n d it appears to b e a mixture of p h o s p h i d e a n d silicide of copper, of sulphate of cupro-acetyle, a n d a variable quantity of acetylide of copper. Its production appears to d e p e n d largely on the p r e s e n c e of a m m o n i a in the crude acetylene g a s ; a n d it shows that the crude acetylene c o n t a i n s phosphoreted h y d r o g e n a n d siliciureted h y d r o g e n . T h e second flask contains a precipitate which is similar in a p p e a r a n c e , but less explosive; a n d the pre, cipitate in the third flask is not explosive. T h e explosive precipitate in the
Jan., 1897. ]
Book ~'otzccs.
77
first flask will explode e v e n u n d e r water, as, for example, when we try to rub it off the glass with a glass rod. "As to the explosibility of acetylene there are two opinions: one, that there may be metallic acetylides formed, which act as detonators to the acetylene itself, so that acetylene c a n n o t be used with reservoirs which are capable of b e i n g attacked by it; the other, t h a t it can only be exploded when mixed with air, a n d that the influence of the outside explosions which can set it off c a n n o t travel far through air. In a n y case, acetylene, at a pressure not much exceeding that of the atmosphere, is not explosive, though it is explosive at pressures a b o v e 2 a t m o s p h e r e s ; so that there is no reason to fear an explosion t h r o u g h flame r u n n i n g back to a reservoir u n d e r a very small excess of pressure. Shock alone does not a p p e a r to cause explosion of the gas, only of the acetylides. T h e alleged poisonousness of a c e t y l e n e - - w h i c h has not, as yet, given rise to a n y a c c i d e n t - - w o u l d a p p e a r to be due to the occasional presence of cyanogen compounds, a n d is not a feature of pure acetylene. T h e presence of sulphureted h y d r o g e n in acetylene seems to depend on that of sulphide of a l u m i n u m in the carbide of calcium ; sulphide of calcium m a y exist in it without forming this impurity. T h e b l o c k i n g of gas jets by acetylene flames seems to be due to the formation of phosphoric acid. If oxygen be not present, acetylene does not attack copper ; the oxide must be formed before the acetylide can be produced." ENGINEERING
NOTES.
A m e a n s for ~breventing t~e noise made by trains in passing over iron bridges has b e e n devised by a G e r m a n e n g i n e e r n a m e d Boedecker. He puts a decking of I ~ - i n c h p l a n k s between the cross girders, resting on 3-inch timbers laid on the bottom flanges. On the p l a n k s a double layer of felt is laid, which is fixed to the vertical web of the cross girder. At the connections with the girder a timber cover joint is placed on felt, a n d two hooked bolts connect the whole firmly to the bottom flange. " Four inches of slag gravel cover the decking,which is inclined toward the center of the bridge for d r a i n a g e purposes. A layer of felt is laid between the p l a n k s a n d the timbers they rest upon, a n d the iron work in contact with d e c k i n g a n d ballast is asphalted. T h e decking weighs 60o pounds per yard for a bridge I I feet wide, a n d costs 23 cents a square foot. It is water-tight, a n d h a s proved very satisfactory in p r e v e n t i n g noise.
BOOK
NOTICES.
Tables Showinff Loss of Head Due to Friction of Water in /:'t~es.
By Edm u n d B. Weston, C.E., M e m b e r of the A m e r i c a n Society of Civil Engineers, M e m b e r of the Institution of Civil E n g i n e e r s of Great Britain. New York : D. Van N o s t r a n d C o m p a n y , 23 Murray a n d 27 W a r r e n Street. 1896. Price, $L5 o. T h e author here presents two tables of flow in pipes, one referring to pipes with very smooth i n n e r walls, such as lead a n d brass pipes, from % inch