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Artificial production of diamonds
Sept., I897.]
Notes and Comments.
239
eral Polytechnic School. T h e Federal Council has been pleased to g r a n t the use of these r o o m s , free of rent, for the projected central laboratory, and thus the great difficulty of location has found its solution in t h e most favorable way. T h e next step, t h a t of finding a fit a n d proper head for t h e central institution, h a s been successfully accomplished b y securing t h e services of a m o s t e o m p e t e n t specialist, H a n n s yon Jiiptner, chief chemist of t h e Neuberg Iron and Steel W o r k s in Austria. Only one step now remains to be taken, raising a fund for t h e m a i n t e n a n c e of the central laboratory, t h a t is, for t h e salaries of t h e director a n d his assistants, for the cost of reagents and o t h e r incidental expenses, a n d further, for r e m u n e r a t i n g t h e assistants of some e m i n e n t chemists in various countries, who have k i n d l y u n d e r t a k e n to take part in t h e work proposed. F o r these purposes $~o,ooo per a n n u m is required, a n d it would be impossible to start t h e laboratory unless t h e p a y m e n t of this expense was secured for, say, ten years. There is no chance of o b t a i n i n g these funds either b y g o v e r n m e n t grants or from t h e institutions existing in various countries. T h e only practicable way is, evidently, to obtain subscriptions from t h e ironmasters of the various important i r o n - m a k i n g countries. L o o k i n g at t h e immense importance such a central laboratory is likely to acquire for t h e whole of t h e iron industry, and t h e very large pecuniary benefit ultimately following therefrom, it is suggested t h a t large iron works m i g h t contribute, say $250 per a n n u m each for that purpose. I t is desirable to have these contributions come from as m a n y countries as possible. It m a y be m e n t i o n e d t h a t t h e firm of Krupp, of Essen, has already subscribed $25o per a n n u m for this purpose, while the Austrian iron masters have made a h a n d s o m e b e g i n n i n g b y subscribing a sum of $1,75 ° per a n n u m . All the other iron-producing nations, it is hoped, will follow. It m a y be added t h a t t h e results secured will be reported at t h e next meeting of t h e I n t e r n a t i o n a l Society, w h i c h will be held at Stockholm, in Sweden, on August 23d. A R T I F I C I A L P R O D U C T I O N OF DIAMONDS. Prof. Win. Crookes gave t h e following i n t e r e s t i n g references to t h e probable origin of t h e diamond, and t h e efforts h i t h e r t o made to produce it artifi. cially, in a recent lecture at t h e Royal I n s t i t u t i o n in London. T h e lecturer stated t h a t speculations as to t h e probable origin of t h e diamond have b e e n greatly forwarded of late years by improved means of obtaining h i g h temperatures ; and t h r o u g h t h e successful experiments of Moissau, microscopic diamonds have been made in t h e laboratory. He had provided a most powerful dynamo, especially made for t h e purpose, weighing 4 ~ tons, and w h e n driven by a 50 to 75 horse-power eugine g e n e r a t i n g a c u r r e n t in the electrical furnace of 7oo to 8oo amperes at 7o volts, yielding a heat of from 3,5oo to 5,ooo ° C. I n the process of m a k i n g diamonds, t h e first necessity was to select pure iron and to pack it in a crucible with pure charcoal from sugar. Half a pound of this iron was t h e n p u t into t h e body of t h e electric furnace and the arc formed close above it to utilize the electrical current passing t h r o u g h it. T h e iron rapidly melts a n d saturates itself with t h e carbon. After a few m i n u t e s it is h e a t e d above 4,ooo°--a t e m p e r a t u r e at which t h e
240
Notes a n d Comments.
[J. F. I.,
lime of t h e furnace melts a n d volatilizes. T h e current is t h e n stopped, and the crucible is p l u n g e d b e n e a t h t h e surface of cold water, w h e r e it is held until it diminishes to a dull-red heat. T h e sudden cooling solidifies t h e outer layer of iron, and holds t h e i n n e r m o l t e n mass in a t i g h t grip. T h e expansion of the i n n e r liquid in solidifying produces a n enormous pressure, a n d t h e dissolved carbon separates out in a t r a n s p a r e n t dense crystalline f o r m - i n fact, as diamond. T h e n commences t h e more tedious part of the process, t h e attacking the metallic mass with solvents to liberate the diamonds, t h e crystals of graphitic oxide, carbonado and b o r t - - t h e cleansing operations b e i n g repeated u n t i l all t h e well-washed grains are collected a n d e x a m i n e d u n d e r t h e microscope. T h e laboratory diamonds b u r n in t h e air before t h e blow-pipe into carbonic acid, a n d in luster, crystalline form, optical properties, density and hardness are identical with t h e n a t u r a l stones. M a n y circumstances, he pointed out, led to the conclusion t h a t t h e d i a m o n d of t h e chemist a n d the diamond of t h e m i n e are akin as to origin, a n d t h a t t h e d i a m o n d genesis must have t a k e n place at great depths, u n d e r enormous pressure. Molten iron could have held t h e carbon in solution, and all t h e varieties of c a r b o n crystals, and even the different tints of diamonds from various mines and geographical areas, could be accounted for on this theory. It is certain, from observations made at Kimberley, corroborated by the experience gained in t h e laboratory, t h a t iron at a h i g h t e m p e r a t u r e a n d u n d e r great pressure will act as t h e longsought solvent for carbon, and will allow it to crystallize out in t h e form of d i a m o n d - - c o n d i t i o n s existent at great depths below t h e surface of t h e earth.. But it is also certain, from the evidence afforded by t h e Arizona and other meteorites, t h a t similar conditions have likewise existed a m o n g bodies in space. P A I N T AS A P R O T E C T I O N TO M E T A L L I C S T R U C T U R E S . T h e D e p a r t m e n t of Public W o r k s of New York City is about to carry out a test of the preservative qualities of various k i n d s of p a i n t w h i c h should be of t h e greatest interest to all engineers and builders, a n d should provide t h e m with some m u c h - n e e d e d data. W e learn from t h e Scientific American t h a t t h e experiments are to be made on a massive steel viaduct w h i c h carries One H u n d r e d and Fifty-fifth Street across the elevated tracks of t h e M a n h a t t a n Railway Company. The test is to be carried out in a t h o r o u g h l y scientific and practical manner, and great care will be t a k e n to shut out a n y disturbing element w h i c h m i g h t affect t h e value of the results. A t i g h t board roof will be built b e n e a t h t h e viaduct to shield it from t h e smoke of t h e locomotives. The first operation will be to clean off all t h e old p a i n t a n d rust by means of the sand blast, and this will be done u n t i l the surface of t h e metal presents a clean and b r i g h t appearance. T h e p a i n t will be p u t on within t h r e e hours from t h e t i m e t h e cleaning is finished. The various manufacturers will be invited to t e n d e r bids and provide specimens of t h e i r paints, a n d these samples will be used in p a i n t i n g t h e structure. T h e precautions w h i c h are b e i n g t a k e n will insure t h a t t h e different varieties of paints will have t h e same opportunities to show t h e i r good qualities, and the results will be watched with close a t t e n t i o n b y those who are responsible for the erection and preservation of all classes of structural steel and iron work.
Notes and Comments.
239
eral Polytechnic School. T h e Federal Council has been pleased to g r a n t the use of these r o o m s , free of rent, for the projected central laboratory, and thus the great difficulty of location has found its solution in t h e most favorable way. T h e next step, t h a t of finding a fit a n d proper head for t h e central institution, h a s been successfully accomplished b y securing t h e services of a m o s t e o m p e t e n t specialist, H a n n s yon Jiiptner, chief chemist of t h e Neuberg Iron and Steel W o r k s in Austria. Only one step now remains to be taken, raising a fund for t h e m a i n t e n a n c e of the central laboratory, t h a t is, for t h e salaries of t h e director a n d his assistants, for the cost of reagents and o t h e r incidental expenses, a n d further, for r e m u n e r a t i n g t h e assistants of some e m i n e n t chemists in various countries, who have k i n d l y u n d e r t a k e n to take part in t h e work proposed. F o r these purposes $~o,ooo per a n n u m is required, a n d it would be impossible to start t h e laboratory unless t h e p a y m e n t of this expense was secured for, say, ten years. There is no chance of o b t a i n i n g these funds either b y g o v e r n m e n t grants or from t h e institutions existing in various countries. T h e only practicable way is, evidently, to obtain subscriptions from t h e ironmasters of the various important i r o n - m a k i n g countries. L o o k i n g at t h e immense importance such a central laboratory is likely to acquire for t h e whole of t h e iron industry, and t h e very large pecuniary benefit ultimately following therefrom, it is suggested t h a t large iron works m i g h t contribute, say $250 per a n n u m each for that purpose. I t is desirable to have these contributions come from as m a n y countries as possible. It m a y be m e n t i o n e d t h a t t h e firm of Krupp, of Essen, has already subscribed $25o per a n n u m for this purpose, while the Austrian iron masters have made a h a n d s o m e b e g i n n i n g b y subscribing a sum of $1,75 ° per a n n u m . All the other iron-producing nations, it is hoped, will follow. It m a y be added t h a t t h e results secured will be reported at t h e next meeting of t h e I n t e r n a t i o n a l Society, w h i c h will be held at Stockholm, in Sweden, on August 23d. A R T I F I C I A L P R O D U C T I O N OF DIAMONDS. Prof. Win. Crookes gave t h e following i n t e r e s t i n g references to t h e probable origin of t h e diamond, and t h e efforts h i t h e r t o made to produce it artifi. cially, in a recent lecture at t h e Royal I n s t i t u t i o n in London. T h e lecturer stated t h a t speculations as to t h e probable origin of t h e diamond have b e e n greatly forwarded of late years by improved means of obtaining h i g h temperatures ; and t h r o u g h t h e successful experiments of Moissau, microscopic diamonds have been made in t h e laboratory. He had provided a most powerful dynamo, especially made for t h e purpose, weighing 4 ~ tons, and w h e n driven by a 50 to 75 horse-power eugine g e n e r a t i n g a c u r r e n t in the electrical furnace of 7oo to 8oo amperes at 7o volts, yielding a heat of from 3,5oo to 5,ooo ° C. I n the process of m a k i n g diamonds, t h e first necessity was to select pure iron and to pack it in a crucible with pure charcoal from sugar. Half a pound of this iron was t h e n p u t into t h e body of t h e electric furnace and the arc formed close above it to utilize the electrical current passing t h r o u g h it. T h e iron rapidly melts a n d saturates itself with t h e carbon. After a few m i n u t e s it is h e a t e d above 4,ooo°--a t e m p e r a t u r e at which t h e
240
Notes a n d Comments.
[J. F. I.,
lime of t h e furnace melts a n d volatilizes. T h e current is t h e n stopped, and the crucible is p l u n g e d b e n e a t h t h e surface of cold water, w h e r e it is held until it diminishes to a dull-red heat. T h e sudden cooling solidifies t h e outer layer of iron, and holds t h e i n n e r m o l t e n mass in a t i g h t grip. T h e expansion of the i n n e r liquid in solidifying produces a n enormous pressure, a n d t h e dissolved carbon separates out in a t r a n s p a r e n t dense crystalline f o r m - i n fact, as diamond. T h e n commences t h e more tedious part of the process, t h e attacking the metallic mass with solvents to liberate the diamonds, t h e crystals of graphitic oxide, carbonado and b o r t - - t h e cleansing operations b e i n g repeated u n t i l all t h e well-washed grains are collected a n d e x a m i n e d u n d e r t h e microscope. T h e laboratory diamonds b u r n in t h e air before t h e blow-pipe into carbonic acid, a n d in luster, crystalline form, optical properties, density and hardness are identical with t h e n a t u r a l stones. M a n y circumstances, he pointed out, led to the conclusion t h a t t h e d i a m o n d of t h e chemist a n d the diamond of t h e m i n e are akin as to origin, a n d t h a t t h e d i a m o n d genesis must have t a k e n place at great depths, u n d e r enormous pressure. Molten iron could have held t h e carbon in solution, and all t h e varieties of c a r b o n crystals, and even the different tints of diamonds from various mines and geographical areas, could be accounted for on this theory. It is certain, from observations made at Kimberley, corroborated by the experience gained in t h e laboratory, t h a t iron at a h i g h t e m p e r a t u r e a n d u n d e r great pressure will act as t h e longsought solvent for carbon, and will allow it to crystallize out in t h e form of d i a m o n d - - c o n d i t i o n s existent at great depths below t h e surface of t h e earth.. But it is also certain, from the evidence afforded by t h e Arizona and other meteorites, t h a t similar conditions have likewise existed a m o n g bodies in space. P A I N T AS A P R O T E C T I O N TO M E T A L L I C S T R U C T U R E S . T h e D e p a r t m e n t of Public W o r k s of New York City is about to carry out a test of the preservative qualities of various k i n d s of p a i n t w h i c h should be of t h e greatest interest to all engineers and builders, a n d should provide t h e m with some m u c h - n e e d e d data. W e learn from t h e Scientific American t h a t t h e experiments are to be made on a massive steel viaduct w h i c h carries One H u n d r e d and Fifty-fifth Street across the elevated tracks of t h e M a n h a t t a n Railway Company. The test is to be carried out in a t h o r o u g h l y scientific and practical manner, and great care will be t a k e n to shut out a n y disturbing element w h i c h m i g h t affect t h e value of the results. A t i g h t board roof will be built b e n e a t h t h e viaduct to shield it from t h e smoke of t h e locomotives. The first operation will be to clean off all t h e old p a i n t a n d rust by means of the sand blast, and this will be done u n t i l the surface of t h e metal presents a clean and b r i g h t appearance. T h e p a i n t will be p u t on within t h r e e hours from t h e t i m e t h e cleaning is finished. The various manufacturers will be invited to t e n d e r bids and provide specimens of t h e i r paints, a n d these samples will be used in p a i n t i n g t h e structure. T h e precautions w h i c h are b e i n g t a k e n will insure t h a t t h e different varieties of paints will have t h e same opportunities to show t h e i r good qualities, and the results will be watched with close a t t e n t i o n b y those who are responsible for the erection and preservation of all classes of structural steel and iron work.