Remembering Eduard Hála

1 Professor Eduard Hála (*9. 12. 1919 in Roudnice nad Labem, †28. 8. 1989 in Prague)

Professor Eduard Hála was an excellent Czech physical chemist and chemical engineer, world-renowned mainly for his fundamental work in the field of vapour–liquid equilibria, a great teacher, and a great personality known to the global scientific and chemical engineering community. He contributed significantly to the development of phase equilibria worldwide. He was a Professor of Physical Chemistry at the Institute of Chemical Technology Prague (now The University of Chemistry and Technology, Prague), member of the Czechoslovak Academy of Sciences, and the deputy director of the Institute of Chemical Process Fundamentals of the CAS.

2 Early Years

Professor Eduard Hála’s father, also named Eduard, came from a farming family residing in the Haná region in Moravia. Some years before WWI he graduated in chemistry from the Technical University in Prague. Before and after WWI he worked in Roudnice nad Labem. During the period known as the First Republic (Czechoslovak Republic 1918–1938), he was a state officer, counsellor for the food industry, and as such was successively moved to the towns of Kolín and Chrudim to which the family followed him.

The young Eduard Hála attended the secondary school (General Gymnasium) in Kolín and then in Chrudim, where he graduated. In autumn 1938 he started studying chemistry at the Czech Technical University (CTU).

On November 15, 1939, he was a member of Honour Guard at the funeral of Jan Opletal. Jan Opletal was a medical student wounded during the protests against the Nazi occupation at the Wenceslas Square on October 28, 1939. He died on November 11 and his funeral turned into an anti-Nazi demonstration by thousands of students. More than 1200 were arrested and sent to concentration camps, 8 students and 1 professor were executed without trial on November 17, 1939. (This was the reason why November 17 was declared as International Students' Day in 1941.) As a part of the revenge, Nazi authorities also closed down all Czech higher education institutions.

Understandably, during the involuntary break, Hála left Prague for Haná and later for Kolín, where he worked in sugar factories and distilleries. Upon his return to Prague, he was employed by the Sugar Research Institute.

After the reopening of the universities in 1945, Hála resumed to his studies and in 1947 he graduated in chemistry from CTU. During the studies, he met Arnošt Reiser, who became his colleague and close friend.¹

Fig. 1

a Arnošt Reiser family arriving in Gedser, Denmark, in 1960. b Arnošt Reiser in 2011

3 E. Hála at the Czech Technical University and Institute of Chemical Technology, Prague (1947–1958)

Hála became a junior lecturer at the Faculty of Chemistry at CTU right in 1947. In 1952, the Faculty of Chemistry separated from CTU and became a core of the newly founded Institute of Chemical Technology, Prague (ICT), a university independent of the CTU. He worked hard at the Department of Physical Chemistry of ICT along (at least) two lines of activities at the time:

• Compiling, classifying, and developing knowledge on vapour–liquid equilibria (VLE), in collaboration with Jiří Pick, Vojtěch Fried and Otakar Vilím, which resulted in “The VLE Book” (see below) and “the Prague school of V-L thermodynamics” brand-name/trademark;

• Lecturing on general physical chemistry (early becoming a senior lecturer) along with Arnošt Reiser; this collaboration resulted in the textbook Physical Chemistry (Vol. 1 and Vol. 2).

It should be remembered that, after the communists seized power in Czechoslovakia, in February 1948, the 1950s were politically the toughest and most oppressive period under the communist rule. Of course, attending scientific conferences was possible only within the, so-called, Socialist Camp countries. Figure 2 shows Eduard Hála among the participants of Phase Equilibria Conference in Kowicz, Poland, in 1957.

Fig. 2

Participants of Phase Equilibria Conference in Kowicz, Poland, May 19, 1957; From left to right: W. Semenesenko, E. Hála, J. Proszt, St. Landa, G. Schay, T. Vrbaski, A. F. Kapustinski, W. Trabczynski, G. Rawicz, Al. Kreglewski, J. Stecki, H. Knopf, H. Kehiaian

Generally, any documentation on the life of Professor Hála is truly very scarce, as a result of his reluctance to participate in any official events and the fact that his entire career fell within the pre-internet era.

4 Teaching Physical Chemistry at the Institute of Chemical Technology

Hála and Arnošt Reiser were given the task of producing records of the physical chemistry² lectures of Professor Ladislav Daneš. However, the underlying documentation (professor´s notes) were so fragmentary and brief that the two were simply forced to learn (quite feverishly) foreign languages and physical chemistry to its full depth and width. They were then together entrusted with lecturing from 1950. They soon recognized the differences between German and English/American ways of teaching physical chemistry. Being inspired inter alia by the G.N. Lewis and M. Randall book on thermodynamics, they acquired and adopted the concepts of activity, fugacity, principle of corresponding states, etc. Their modern lectures became very popular and were highly attended. The two volumes of the essential university textbook of physical chemistry based on their lecturing experience [1, 2] are used by physical chemistry teachers until this day.

Despite the unfavourable overall atmosphere in the society, the department succeeded in maintaining the collaborative team spirit at the Department of Physical Chemistry, to which Hála substantially contributed. One dare say that it was one of the strongest, most renowned, and respected scientific groups in the field at the time. Figure 3 shows the members of the Department in May 1958.

Fig. 3

Department of Physical Chemistry at the Institute of Chemical Technology, Prague, on May 22, 1958. Bottom row from left: Emerich Erdös (working on catalytic reactions), Arnošt Reiser, and Eduard Hála; also seen: Julius Pouchlý (working on catalytic reactions), Jaroslav Nývlt (working on crystallization), Tomáš Boublík

However, later in 1958 the “political examination committees” started acting, which lead to political purges at universities. As a result, Hála and some of his “politically unreliable” colleagues were forced to leave ICT (not to spoil the young generation). Nevertheless, many of them could at least somehow continue their work at the institutes of the Czechoslovak Academy of Sciences (CSAS).

5 The Vapour–Liquid Equilibrium Book

The comprehensive efforts on vapour–liquid equilibria (VLE) were initiated by Professor Otto Wichterle, an organic chemist with a highly developed sense for the practical applications of scientific research results. Thus, the outcome of the work, the book on vapour–liquid equilibria [3] in 3 parts: Thermodynamics of Nonelectrolyte Solutions, Experimental Techniques, and a VLE Data Bibliography (including 30 pages of references for all binary and multicomponent systems available by April 1954) was intended for a wide spectrum of readers ranging from research scientists to industrial chemical engineers.

Based on the success and response of the expert community, the monograph was soon revised by the authors and translated to English by George Standart. The first English edition came out in 1958 and contained VLE Data Bibliography for data available in literature by February 1957 [4]. The second, substantially revised and extended English edition came out in 1967 [5]; VLE Data Bibliography compiled by July 1965 already occupied 240 out of the total 600 pages, manifesting the explosion in experimental activities on VLE in that period.

The book represents a classic (so to say “a bible”) of this field of research and one could find it on the shelves and workbenches in thermodynamics departments worldwide.

6 E. Hála at the Institute of Physical Chemistry of the CSAS (1958–1964)

After he had to leave ICT in 1958 Prof. Hála found a new place of work at the Institute of Physical Chemistry of the CSAS (IPC). He had established a small research group (Tomáš Boublík, Ivan Wichterle and Karel Hlavatý) that operated in quite cramped conditions. At the time IPC was located at “Máchovka”, a building originally designed to accommodate nuns.

The group worked on research on SO₂ absorption in water and in aqueous NH₃ solutions, designing suitable experimental techniques while E. Hála developed a general correlation method for VLE systems with electrolytic components. At the same time Hála worked on finishing the second volume of the Physical Chemistry textbook and started working on revising the first volume of the textbook as well as the book on VLE.

One should realize that the second volume of the Physical Chemistry textbook was completed in mid-1960s, i.e. some years after A. Reiser left the country. Hála saw to proper inclusion of Reiser’s parts of text and also insisted that the coauthor’s (who was an emigrant!) name be retained on the title page, which, under the circumstances at the time, was an act of heroism on his part.

7 E. Hála at the Institute of Chemical Process Fundamentals of the CSAS (1964–1969)

In 1964 new premises for the newly established Institute of Chemical Process Fundamentals of the CSAS (ICPF) were finished in Suchdol. Its initiator and founder, Professor Vladimír Bažant, invited Hála and his group to move in. Two postdocs (Jiří Polák and Jan Linek) and gradually other coworkers joined the group forming so the Department of Chemical Thermodynamics at ICPF.

In part, the group carried out research on demand for industry, focused on studying VLE of multicomponent nonelectrolyte and electrolyte systems, including K₂O–SO₂–C₆H₅COOH–H₂O. Also, owing to industrial needs, Vladimír Bažant initiated work on compiling VLE data. Tables of correlated VLE Data for a number of systems, selected on the basis of practical importance, data quality and representation of different group combinations in Ewell's classification of liquids, were published in the book released in 1968 [6].

As a consequence of a (temporary) easing of the political situation in mid-1960s, Hála was eventually allowed to resume teaching at ICT. He was also actively steering the group, gently directing people to promising topics, fields, and projects: Tomáš Boublík towards statistical thermodynamics, with stay at National Research Canada, Ottawa, Ivan Wichterle towards high-pressure VLE, with stay at Rice University, Houston, Jiří Polák towards VLE data processing and Wichterle along with Jan Linek, towards continuation of compiling VLE Data Bibliography, which pioneered presentation in a computerized form.

A noteworthy result at the time was a book on statistical thermodynamics [7] “rectified” from lectures of Hála and seminars of Boublík on the subject at ICT. The monograph already contained inter alia the liquid theory (including Van der Waals equation, cell theory, and radial distribution function method) and the theory of nonelectrolyte solutions (including the lattice theory and the theorem of corresponding states).

8 Years 1969–1980 with E. Hála

In summer 1969, I was invited to ICPF and in October met Professor Hála in person for the first time. After being interviewed by him and Boublík, I was deemed capable of working on my MSc thesis at the department, under the supervision of Boublík. That is how my opportunity to get to know the great person started.

Soon I found that Hála possessed natural authority and was highly respected by the entire staff of ICPF, having rare ability to lead people without seeming to do so. Very early I recognized his way of hints and memos and his sense of humour (often amiable irony). At the same time he was rather private and introverted (almost never speaking about personal things); he was always succinct, concise, apt, and to the point, often using his personal expressions and ways of communication.

Above all, Hála was inconspicuously maintaining the fair, decent and friendly atmosphere in the department, with his profoundly calming influence.

It was typical of him that once he formed his opinion on someone and selected the person as a collaborator, he rarely changed his mind. He rather started trusting the person completely and providing him/her with his full support in every possible way. This showed fully in his generosity, patience and, with us “young ones” in his leniency towards our small lapses.

Members of the department in early 1970s are displayed in Figs. 4 and 5, while Fig. 6 shows Hála lecturing at conferences: (a) Liblice 1977, (b) Merseburg 1980.

Fig. 4

Department of Chemical Thermodynamics at ICPF, August 2, 1971; Top row from left: Tomáš Boublík, Karel Hlavatý, Ivan Wichterle, EH, Jan Linek; Bottom row from left: J. Mikšovský, J. Vejrosta (PhD students)

Fig. 5

Department of Chemical Thermodynamics at ICPF in 1973; New members: Karel Procházka (2nd from left), Karel Aim (5th from left), Jarka Polednová (technician)

Fig. 6

E. Hála lecturing at conferences: a Liblice 1977, b Merseburg 1980

For a period of several years during the 1970s Hála held the post of deputy director of ICPF and after the untimely death of Vladimír Bažant in 1973, he was acting director of ICPF for about two years. He was also elected Academician (of the CSAS) and a member of the Presidium of the CSAS. Being the only non-member of the Communist Party at the Presidium, his role was quite specific in the peculiar decision processes of those times. Hála had a strong sense of proportion and therefore often must have been prone to frustrations that he only intimated to us. Attending official events related to his activities at the Presidium equally was not his cup of tea. In general, he was not fond of any publicity, celebrations, and ceremonies. On such occasions he often gave a sigh, saying “I’ve yet again had to sit it out, guys”.

Not much was known about his avocations. His primary hobby must have been classical music. It is known that for decades a string quartet of Hála and colleagues met weekly at his apartment. Originally, he played violin, but after the emigration of Arnošt Reiser (who had played viola), Hála had to retrain himself for the viola.

In his younger years he did not avoid sports. He played volleyball and it is also known that soon after WWII, during his shortened military service, he was a member of the winning team in a state-wide volleyball competition.

Even Hála had his weaknesses and in some instances exhibited a certain degree of vanity and self-conceit. He liked playing chess and loved kibitzing but was not a very good player. He hated losing though, so when in a spare moment he challenged one of us to a game of chess, we knew we would have to play long enough to eventually let him win.

9 E. Hála in 1980s

In the 1980s, Hála was already less active in research, working alone on correlation relations for systems with electrolytes and on some review articles. However, he continued keeping himself fully up to date on what was happening in the broader field of research, closely following several promising lines of research, including the group contribution methods for activity coefficients and the so-called augmented Van der Waals equations of state, notifying us of anything interesting he came across and, from time to time, giving us various tasks.

One of these was to produce a concise “VLE Book” with updated chapters on the correlation and representation of VLE data, which included a package of FORTRAN programmes for the estimation of parameters using “classical” (Margules and Redlich–Kister) and “non-classical” (Wilson, NRTL, and UNIQUAC) equations for excess Gibbs free energy and for the calculation of VLE data in multicomponent systems from binary parameters. This was published in 1982 [8] but some of the computer programmes are still used today.

The members of the Department of Chemical Thermodynamics at ICPF at that time are seen in Fig. 7.

Fig. 7

Department of Chemical Thermodynamics at ICPF in August 1983; New members: Ivo Nezbeda (top row, 2nd from left), Zdeněk Wagner (bottom row, 5th from left), I. Červenková (research assistant)

Hála also continued participating in scientific conferences. In 1983 he was invited by John Prausnitz to attend the 3rd Conference on Fluid Phase Equilibria for Product and Process Design (FPEPPD) in Callaway Gardens, GA, USA. He attended and returned in enthusiastic mood, full of new ideas on what to do next. He also regularly attended the International CHISA Congresses in Prague (see Fig. 8).

Fig. 8

E. Hála and I. Wichterle at CHISA Congress in 1987 (last photo of EH)

10 1989

During late 1980s Hála increasingly suffered from Parkinson’s disease. According to his son, Jan Hála, in the beginning of 1989 Hála felt rather exhausted and not well. In the summer, he was diagnosed with acute pancreas inflammation and had to undergo surgery. However, he was not able to overcome post-operative complications and passed away on August 28, leaving us shocked and deeply saddened.

In central and eastern Europe, 1989 was a year of political developments, actions, and systemic changes. Unfortunately, due to his untimely death, Hála missed the November Velvet Revolution which started the transition of Czechoslovakia back to democracy, by a mere 3 months.

During that year we prepared a special issue of the Collection of Czechoslovak Chemical Communications [Vol. 54 (11), November 1989], originally designed to celebrate Hála’s 70th birthday. So, in the end the issue came out as a commemorative edition.

11 Post-Hála Years, the E. Hála Laboratory of Thermodynamics

As a tribute to EH, annual Eduard Hála Lectures have been organized since 1999. In October of 1999, on the occasion of the 80th anniversary of his birth (and 10th anniversary of his death) we organized a two-day commemorative E. Hála Symposium. Arnošt Reiser was invited to present the 1st Eduard Hála Lecture at the event; he gave an excellent speech entitled “Remembering a Friend”, (see Fig. 9). Ever since, the Eduard Hála Lectures are delivered at ICPF by renowned specialists on topics investigated at the Institute. For a complete list of Eduard Hála Lectures see https://www.icpf.cas.cz/en/e-Hála-lectures/.

Fig. 9

Arnošt Reiser delivers the 1st E. Hála Lecture at the E. Hála Symposium (October 8, 1999)

In 2008 the management of ICPF asked Professor Zdeněk Herman (from the J. Heyrovský Institute of Physical Chemistry of the CAS) to create a bust of Eduard Hála. The outcome of his work was more than well-made and the bust of EH was unveiled in the entrance hall of ICPF on the occasion of 10th E. Hála Lecture (given by Jan Genzer) on 10th October 2008, see Fig. 10.

Fig. 10

Bust of Professor E. Hála (created by Professor Zdeněk Herman from JH IPC) in the entrance hall of ICPF

During the 12th European Seminar on Applied Thermodynamics in Berlin in 1991 Professor Jakob de Swaan Arons came up with the idea to name the department after Hála, so soon after that we became the E. Hála Laboratory of Thermodynamics (EHLT). While Tomáš Boublík left ICPF for Charles University in 1992, EHLT was headed by Ivan Wichterle until 2005, then by myself until 2012. In the evaluation exercise of CAS institutes and research teams (for period of 2005–2009) that took place during 2010–2011, EHLT was assessed as the best department at ICPF. The successful team, in fact the largest in size in the department history, is shown in Fig. 11.

Fig. 11

E. Hála Laboratory of Thermodynamics at ICPF in 2009—From left to right: J. Linek, M. Bendová, Z. Sedláková, K. Machanová, M. Lísal, I. Nezbeda, K. Aim, S. Pařez, I. Wichterle, J. Pavlíček, M. Předota, and Z. Wagner

On the reorganization of ICPF implemented in 2013–14, the group of the stand-alone E. Hála Laboratory of Thermodynamics became part of a larger E. Hála Laboratory of Separation Processes, whereas some colleagues joined another department. As a result of the second reorganization of ICPF in 2017, the group of former EHLT was practically dismantled; its members are now working in 3 different units, while the name of Eduard Hála tacitly disappeared from the designation of any section of ICPF.

Apart from the scientific literature and besides our memories, the above mentioned bust and annual lectures, Hála is also remembered by the J. Heyrovský Institute of Physical Chemistry of the CAS in their Gallery of Founders and Personalities (https://web.jh-inst.cas.cz/cs/zakladni-stranka/galerie-zakladatelu-osobnosti-ufch), see Figs. 12 and 13.

Fig. 12

Gallery of Founders and Personalities at the J. Heyrovský Institute of Physical Chemistry of the CAS: Top row, 2nd from left: Jaroslav Heyrovský (Nobel prize in chemistry, 1959); Bottom row, 3rd from left: Eduard Hála

Fig. 13

Gallery of Founders and Personalities at the J. Heyrovský Institute of Physical Chemistry of the CAS: Graphics of Eduard Hála and Jaroslav Heyrovský by Zdeněk Herman

In 2014, a booklet containing personal memories of several of Hála’s collaborators and colleagues (revealing quite a lot about his personality, especially about his magnanimity and nobility of character) and including also the E. Hála Lecture presented by Arnošt Reiser in 2009 was issued by Academia publishing house in a Series SCIENCE AROUND US [9]; the English edition of the booklet can be downloaded from http://www.vedakolemnas.cz/osobnosti/140803-eduard-Hála-en.html.)