8.1 Research Interests

Carl Auer von Welsbach made his great discoveries and important inventions in only the space of the twenty years after he completed his studies with Robert Bunsen . In that amount of time, he accomplished far more than most scientists achieve in an entire lifetime of research. As this intense research period began to wind down, he was able to turn his mind to other things—some of a more personal and recreational nature, some with an outward thrust to the scientific world in general, and some to the care and nurturing of his fellow human beings. In all of these new undertakings, the skills he had gained previously were put to work in new contexts.

8.1.1 Research Chemicals for the World

As we have seen in previous chapters, Auer von Welsbach developed his rare earth separation skills to a point that they were unmatched by other scientists of his time. Through his expertise, he was able to provide the purest samples of these elements possible at the time. Thus, it was natural that when the Austrian Imperial Academy of Sciences saw the need to begin a large-scale, industrial radium production project to supply the radioactivity community with large, research-grade amounts of this precious commodity, they turned to him for guidance and factory space. The well-known geologist Eduard Suess (1831–1914), who was then President of the Academy, commissioned the work, a significant move for the development of nuclear physics for the next 30 years.Footnote 1

Because he and his co-workers at his factory in Atzgersdorf (Fig. 8.1) had years of experience in extracting thorium and cerium from the minerals in which they were contained, Auer was conveniently placed to provide the necessary infrastructure and experience to extract radium from the pitchblende residues from the Joachimsthal mine , located at that time within the borders of the Austro-Hungarian Empire.

Fig. 8.1
figure 1

The Atzgersdorf factory (about 1900)

Full size image

So, in March of 1904, he gladly placed his Atzgersdorf factory at the disposal of the Academy, thus setting up the mechanism for the first industrial production of radium compounds in the world. This catapulted Austria into a position equal to France as a center of radium standards and a calibration center for radium preparations for numerous governmental, scientific, and health-related entities.Footnote 2 Auer financially supported much of this enormous endeavor out of his own resources. He delegated his long-time assistants, Ludwig Haitinger , Karl Peters, and physicist Carl Ulrich, to devise the extraction process. Bohemian pitchblende from the Joachimsthal mine (the original source of the raw materials used by Marie (1867–1934) and Pierre Curie (1859–1906)), with an average uranium content of 53.4%, was treated with sodium sulfate to produce sodium uranate, which was subsequently dissolved in dilute sulfuric acid. The radium remained in the residue. Haitinger, Peters, and Ulrich were able to extract 3.0 g of radium chloride and 0.236 g of radium bromide from 10,000 kg of pitchblende (about 11 US tons).Footnote 3

At that time, the following quantities of raw materials were required to produce a gram of radium: ten tons of ore, three tons of hydrochloric acid, one ton of sulfuric acid, five tons of soda, and ten tons of coal. In addition, it took two months of work in the laboratory to purify the radium. In 1911 the chemist Otto Hönigschmid (1878–1945) (Fig. 8.2), a world-famous atomic weight specialist,Footnote 4 was able to determine its exact atomic weight by means of the high-purity Atzgersdorf radium.

Fig. 8.2
figure 2

Otto Hönigschmid

Full size image

Radium was at that time a very precious element since it was indispensable for the initial radiotherapy for cancer control, thus rendering a gram of radium worth more than the price of 260 kg of gold in 1914. This spurred searches for more efficient separation methods. Since a ton of uranium ore contained only 0.1 g of pure radium on average, it was like looking for the proverbial needle in the haystack.

Between 1907 and 1909, thanks to Auer’s expertise and generosity, the Vienna Academy was able to furnish radium to learned societies and institutes in Britain and the continent at a nominal cost. The Academy, in addition to aiding the Curies, provided samples on loan to Ernest Rutherford (1871–1937) and William Ramsay (1852–1916) , among others. Impressed by these accomplishments, the lawyer-industrialist Dr. Karl Kupelwieser (1841–1925) endowed the Academy with 500,000 crowns (equivalent to five million euros) to build an institute for radium research. The institute was opened in 1910 by Stefan Meyer (1872–1949) and was active until 1938. Auer von Welsbach ’s radium was the institute’s most important research material.

The residues from radium production were also subjected to analysis for other elements and compounds of interest, among which were thorium and actinium. Thorium was of particular interest because it was believed to contain two elements, thorium and ionium ; the latter was suspected of being the mother substance of radium. Auer von Welsbach failed to separate ionium from thorium, which is not surprising given that ionium, unbeknownst to Auer at the time, is an isotope of thorium, 230Th. This was clarified only after the concept of isotopes was proposed by Frederick Soddy in 1913. It was also found that the percentage of ionium in mineral sources varied with location. Otto Hönigschmid determined that the ionium content in the Auer von Welsbach preparations was 30%.

Because of their ultrahigh purity, it was Auer’s rare earth preparations that enabled physicists like Niels Bohr in Copenhagen, Ernest Rutherford in Cambridge, and Stefan Meyer in Vienna to determine the inner-electron shell structure of the entire series of rare earths from lanthanum to lutetium . These measurements showed that lutetium exhibited a closed-shell, a fact that Bohr capitalized on by theorizing that the next element beyond lutetium should be the higher homolog of zirconium, thus paving the way for its discovery, named hafnium , by George de Hevesy and Dirk Coster in 1923, as described previously in Chap. 4. In addition, two years later, Friedrich Hund (1896–1997) , in Göttingen, formulated the rules for the spin coupling of multi-electron systems (Hund’s Rules) and from them was able to deduce the magnetic properties of the rare earth elements. He was able to verify this theoretical work, a major step in the advancement of quantum theory, by comparing it with Stefan Meyer ’s experimental work based on samples provided to him by Carl Auer von Welsbach .Footnote 5

Anyone who applied to Carl Auer von Welsbach with a request for lanthanide or actinide compounds came into possession of priceless ultrapure chemicals not available anywhere else in the world. As a rule, Auer listed when, where, and to whom he supplied the deliveries of more than 500 specimens, and so distinguished names were found among his hitherto unknown grateful customers, such as Niels Bohr , Dirk Coster , Francis Aston (1877–1945), George de Hevesy , Otto Hönigschmid , Manne Siegbahn (1886–1978) , Ernest Rutherford , and Friedrich Wöhler .Footnote 6 Figure 8.3 is a graphical representation of his “distribution list.”Footnote 7

Fig. 8.3
figure 3

Number of Contacts through Distribution of Auer’s Rare Earth and Radiochemical Preparations

Full size image

8.1.2 Radium Today

Radium was the most important material for research in nuclear physics in the early years of the 20th century. It was only when the first particle accelerators were developed in the 1930s that its significance began to decline. At the Institute of Radium Research, however, the radium was conserved, despite this diminishing importance, without any real use for it. However, in the year 2000, this radium was put to an unexpected use. At the Technical University of Munich , a group of nuclear physicists, radiochemists and nuclear physicians, with the support of the US company Actinium Pharmaceuticals, had turned to the production of the radioisotope actinium-225 (225Ac) for alpha-immuno-cancer therapy. The basic idea is to attach the relatively short-lived radioisotope, Bismuth-213 (213Bi, t1/2 = 45.6 m), to an antibody molecule that has a specific affinity for cancer cells. When the antibody molecule has docked at the cancer cell, beta decay of the 213Bi to the extremely short-lived 213Po (t1/2 = 4 ps) produces the immediate emission of alpha particles with an energy of 8.4 meV which can now destroy the cancer cell at close range. In order to have the 213Bi available in a clinical application, you need a slightly more long-lasting mother substance (a “radioactive cow”) from which you can “milk” the 213Bi as required. The above-mentioned 225Ac (t1/2 = 10d) is a favorable starting material. This is where the 226Ra comes into play: 225Ac can best be generated by the nuclear reaction 226Ra + p = 225Ac + 2n. For this purpose, a 226Ra target is needed, a most suitable use for the remaining radium at the Radium Institute, viz. 2.1 g. A fitting end to the feverish production efforts of earlier times.Footnote 8

8.1.3 A Word of Caution

The damaging effects of radium were underestimated even by scientists. Soon after its discovery, it was thought to be the long-awaited and hitherto undiscovered elixir of life. Since low-dose irradiation led to noticeable healing, it was concluded that higher doses would lead to better results. As a result, radioactive-doped wipes and toothpastes, as well as apparatus for inhaling radioactive gas (radon), flooded the market unchecked and therapeutic radium baths were offered all over the world. Prescribed dosages were often exceeded at the request of preoccupied patients because they assumed that more was better. The harmful effects of radiation only became apparent after long use, so it took quite some time to establish safe exposure guidelines. The voice of Paracelsus (1493–1541) could be heard once again after four hundred years, “All things are poison and nothing is without poison; only the dose makes a thing not a poison.”Footnote 9

8.1.4 A Mysterious Observation

Even after Auer gradually became aware of the deleterious effects of his actinide and thorium preparations, he did not abandon his research, continuing to work heroically and perseveringly in the service of science to gain new insights. He contributed a detailed note, labeled Part I in the conference reports of the Academy of Sciences in Vienna on this work, carried out before 1910, in which he isolated a substance he called ionium from thorium oxide.Footnote 10 Part II was never published.

In a newly-discovered 1910 manuscript in preparation, which now seems to be the missing Part II, Carl Auer von Welsbach reported a “mysterious observation”,Footnote 11 namely, seemingly induced radioactivity in a platinum crucible placed in “long-lasting contact” with a sample of ionium.Footnote 12 After unsuccessfully trying to remove suspected superficial contamination, Auer predicted that this observation could possibly be important for subsequent research: the prevailing theory, of which Auer was well aware, was that a radioactive substance could not activate an inactive material. Modern speculation posits. neutron activation as the cause of the effectFootnote 13 The possible neutron source was hypothesized as arising from alpha-particle reaction with beryllium, a common substance in the residues that Auer was working with, to yield a neutron and 12C according to the reaction 9Be(α,n)12C. The hypothetical activation product was 194Ir. Two problems with this idea is that the neutrons produced are not thermal, yet no possible moderator could be suggested, and that there was no iridium present in the crucibles examined, especially the one that was suspected to have been the subject of Auer’s observation. The authors admitted that more historical forensic work had to be done in order to carry this idea forward. They are especially on the lookout for possible candidates for Auer’s original crucible.Footnote 14

It should be mentioned that although Auer published little in his long experimental lifetime, he never left off chemical research despite the numerous hobbies that he took up in his later years. Hence, it is exceptional that after a lengthy hiatus, at the age of 63, he wrote and published a long treatise on spectroscopic methodology in analytical chemistry .Footnote 15 In this paper, he describes his state-of-the-art dual-purpose spark gap apparatus (for both visual observation of spectra and for photographing them) with four images of the apparatus and a sample set of the spectra obtained. At the end of the paper, he promises a sequel publication, and then a collection of the entire treatise with additional illustrations in book form, a promise that was never fulfilled. This was to be his final scientific publication with the exception of his 1926 paper describing his futile hunt for element 61 (See Chap. 4, Sect. 4.4.2.)

8.2 Domestic and Recreational Interests

Despite his many business connections and interests, and despite the fact that he had a working laboratory on the ground floor of his castle that he frequented every day, mostly at night when everyone else was sleeping, Auer developed an intense interest in so many areas that one might say that he “invented” the career of full-time hobbyist.

It may have been difficult for Maria Auer von Welsbach to function as the wife of this famous man, given the fact that she had originally been hired for office work and research. But her love, youth, and joy of life triumphed. With great respect, empathy, and clever planning, she managed to shield her husband from the numerous trivialities that would interrupt him, allowing him all the time he needed for his scientific and entrepreneurial activities. However, he also spent a great deal of time with his children, teaching them the mechanical skills they would need as they matured and sought out their own vocations as adults (Fig. 8.4). As his children grew older, he drew them into his confidence and came to depend more and more upon his sons, especially as his deafness increased.

Fig. 8.4
figure 4

Carl Auer von Welsbach working in a shop with his sons Carl and Hermann

Full size image

His work schedule was rather unusual, but the family was habituated to it. After breakfast around 10 AM he worked until lunch at 2 PM. Afterwards, he worked until he took a break at 9 PM, when he had dinner in the family circle. His peculiar habit from his student days of working far after midnight he maintained until the end of his life.

His mother, Therese Auer von Welsbach , frequently traveled from Vienna to visit her youngest son and his family at Welsbach Castle. During her stays, Auer and his wife always took the best possible care of her. She became the source of family history for her grandchildren and, of course, regaled them with stories of the exciting events in the capital.

8.2.1 A Variety of Hobbies

Auer’s many interests included hunting and fishing, which he enjoyed very much. His large estate gave him ample opportunity to sally forth with gun or rod and reel in hand. He also employed a butterfly net, and built an extensive collection of the indigenous butterflies and moths of the Carinthian region which can now be found in the Natural History Museum in Vienna. His other collecting specialty was minerals, consisting primarily of rare earth and thorium minerals. And, of course, the thorium mineral Auerlite,Footnote 16 which was named in his honor, gave rise to correspondence from all over the world. This fact led to a bit of stamp-collecting as well since he arranged the various stamps he received in an orderly fashion.

He was already an enthusiastic car owner by 1902. At the time, a chauffeur-mechanic was provided by the manufacturer when the car was purchased. This was the person who had assembled the car and knew the detailed functions of the engine, and how to do the frequent necessary repairs. For this reason, the automobile manufacturer Gottlieb Daimler (1834–1900) predicted shortsightedly: “The global demand for cars will not exceed one million worldwide—if for nothing else due to a lack of chauffeurs.”Footnote 17 Besides needing a resident mechanic, early automobile owners also needed a lantern carrier to run ahead of the car after dark because there was no street lighting at all. Auer avoided this legal requirement by equipping his car with his own invention , the metal filament lamp, as early as 1906. In the interests of safety and convenience, Auer also financed the acquisition and installation of international traffic signs for Carinthia .

And his interest in sound recordings resulted in some that can be heard to this day, given the correct equipment! This all began when he met Thomas Edison to compare the latter’s carbon filament lamp with his own metal filament bulb, and discovered that Edison had invented a sound-recording device that he called a “phonograph.” At the end of a sound-directing funnel was a so-called sound box, which had a diaphragm which could be excited by sound waves. In the middle of this membrane, where the vibrations were most pronounced, a pointed needle was attached so that its mobility was not restricted too much. With this device, it was possible to engrave sound signals on a wax cylinder rotating uniformly on a shaft.

In 1900, Auer began to produce sound documents—“home recordings”—using the twenty wax rolls that came with the device. At the beginning of each recording, Auer himself explained which persons could be heard on the roll in question, including not only his mother, who was born in 1831, but his wife, the directors of his companies, the builder of his castle, his forester, etc., and also the staff working in the castle. These original rolls, with an average running time of 3.5 min each, were found nearly 100 years later at his estate. The Austrian Academy of Sciences Acoustic Research Institute in Vienna was able to digitize them so that the voices could be easily understood. Uncanny voices from the past!

Following in the footsteps of his father Alois, who invented the nature self-printing process (see Chap. 1), Auer was successful not only as an inventor, discoverer and entrepreneur , but also as a talented artist of light. A pioneering photographer who is credited with producing the first color photograph in Austria, he was using the French Autochrome method introduced by the Lumière brothers as early as 1908, just a year after it became commercially available.Footnote 18

Photography, at that time, was a luxury affordable by only the very wealthy since every camera, and its accompanying lenses, had to be individually made to order. Auer had an advantage as both a spectroscopist and a chemist: he had his lenses made specially for him by the Steinheil Company of Munich, provider of his personal spectroscope ; his familiarity with chemicals enabled him to set up his own working darkroom to develop his glass photographic plates in a carefully controlled setting. As a result, his archival color photographs come very close to today’s standards.

The family photographs, which he took between the years 1900–1920, are unique. Those of his four children in various activities are an impressive record of an upscale lifestyle during the declining years of the Austro-Hungarian monarchy. They also are precious documents at the very beginnings of color photography and stereophotography. In view of the extensive and heavy photographic equipment necessary and the low sensitivity of the photoemulsions, photography at that time was not suitable for anything but still shots within a limited range. Without a tripod, no photo shoot was possible. That is why virtually all of Auer’s photographs were taken within a few kilometers of Welsbach Castle. In addition, exposure times of several seconds in full sunshine were required for any kind of good resolution. That is why it is quite surprising how his four children (Fig. 8.5) could stay still at the same time. However, they were not always so good; this is evident by some blurring in a number of the photos, a problem that only appeared after the development of the photoplates.

Fig. 8.5
figure 5

The four Auer children enjoying a dip in a spring. 1908

Full size image

Auer’s various types of photographs range from micro-, macro- and stereophotography in black and white and color. There was no other amateur photographer of the time who dabbled in so many genres of photography with such high-quality results.

8.2.2 Botanical Ambitions

Auer managed his extensive estate personally, sometimes even pruning his own rose bushes and fruit trees by hand. When he cut back the vines in February, the only task that the gardener who accompanied him had was to hand him his tools: like a virtuoso surgeon, he insisted on doing, very meticulously, the actual cutting himself.

He took great joy in not only raising flowers, but in developing his own varieties. One of his prize roses had a deep, red-black tone that was very rare at the time. And with endless love and patience he cultivated the laboriously acclimatized Lebanon cedars, chestnut trees, magnolias and the other exotic trees that he had imported into his estate.

In 1897, Auer extended the estate’s orchard, planted with many different types of apple trees, to 8 ha; it was later extended to 30 ha. He appreciated the many different apple varieties he had, but remaining unsatisfied, he enthusiastically began cultivating a new variety. The result was a deep red, slightly acidic, highly aromatic apple, which could easily be stored for up to ten months due to its low sugar content. Such a delicious apple with the characteristics described above was previously unknown. In honor of its developer, it became known as the “Auer von Welsbach apple” (Malus domestica-Auer von Welsbach ), a new variety of the Canadian Reinette, an old French cultivar of domesticated apple which Auer refined to his liking. The neighboring municipality of Althofen liked it too: today this apple tree can be found in the public parks and private gardens around the town.Footnote 19

8.3 A Generous Community Member

Carl Auer von Welsbach not only provided the world with light and fire through his inventions, but he also lightened the burden of many members of his community, both in Carinthia and in Vienna. Mention has already been made of his donation of time, space, and means to the research establishments of Vienna and the rest of Europe (Sect. 8.1). He also gave large amounts of money to needy people, associations, hospitals, relief organizations and, institutions so as to benefit not only the general public, but also individual persons. His generosity extended to his local community in Althofen, Meiselding, and the surrounding towns of Carinthia in a personal and caring manner: when he noticed a need, he hastened to fill it in a particular way. For example, he realized that children living in the area of Sankt Veit an der Glan lacked adequate clothing during a particularly difficult economic period, and were especially needy during the winter season. So, in 1898, he provided about 3200 children in need of help with winter clothes and shoes. All the tailors and shoemakers in the area had their hands full trying to deal with this huge order by Christmas.

In 1904, the hospital at St. Veit was also a beneficiary of his generosity in the form of an X-ray apparatus that placed it in the forefront of diagnostic treatment in the area. At that time, the hospital did not yet have the necessary electrical system to operate the device. The diesel generator donated by Auer for the hospital’s use was put to multi-tasking: when the X-ray machine was not in operation, it was used to drive a circular saw to cut firewood. In place of the hospital’s unhygienic wooden beds, Auer provided modern iron beds—he seemed to notice every problem and took immediate measures to correct them.

He used a great deal of his wealth to help his own employees. He constructed housing for his workers and included an ample plot of land with each house for use as a garden and recreational space. For the workers who might need to work overtime, he equipped the factory with modern showers and bathtubs. He also saw to it that his workers all had good working conditions and auxiliary benefits, measures that were unheard of in his day.Footnote 20

His commitment to social justice was not limited to his workers, but extended especially to the next generation. He consistently checked that the children in the Treibach region had shoes and a daily ration of milk. To assure that this occurred during World War I, he even purchased milk cows to provide as much as 1000 L of milk daily to schoolchildren as a rickets-prevention measure; he even commandeered is own car to serve as a delivery van in the absence of any other transport method.

Perhaps his most significant and lasting contribution to the younger generation was the rebuilding of the Volksschule (primary school) in the Mölbling-Meiselding school district. It was completed in 1908 on the occasion of the 60th anniversary of the reign of the Emperor Franz-Joseph, in whose honor it was dedicated as the Kaiser Franz-Josef Jubiläumsschule.Footnote 21 The new school filled a dire need in the area: the old building not only was too small, but it was so humid, drafty, and insalubrious that it had to be closed periodically because of epidemics of mumps, measles, scarlet fever, and other diseases among the children. The new school building, begun in 1906 and financed entirely out of Auer’s resources, was a model educational center with elegant classrooms, a conference room, a gymnasium, a school kitchen, a telephone communications system, and a fully-equipped teacher’s living quarters.

Auer’s philanthropic activity was vast and sustained. While it may never be known to what extent he deployed his resources in this way, what is known is that his beneficial expenditures between 1896 and 1914 alone amounted to almost twice the purchase price of his villa and castle combined, and in 1919, he donated the entire amount realized in the sale of his Viennese palace to charity.Footnote 22 In all of his charitable giving, Auer tried to remain in the background, but often unsuccessfully. When, during World War I, he gave a considerable donation to charity, he was told that an official Act on the subject had to pass through the emperor’s cabinet office, so he immediately specified that it be anonymous.Footnote 23 However, in recognition of his great generosity, the city of Klagenfurt, capital of Carinthia , made Carl Auer von Welsbach an honorary citizen of the first rank.