Before the Second World War, the Chemical Laboratory of the State Company of Artillerie-Inrichtingen (A.I.)  [1] was located at Julianalaan 134, Delft. By order of the occupying German forces, the Julianalaan was renamed Poortlandlaan. The following undated post-Liberation of The Netherlands (May 1945) report discusses the transition of the Chemical Laboratory from the A.I. to T.N.O.. This laboratory was the predecessor of the TNO Technological Laboratory of the TNO National Defence Organisation which was established in 1949. That laboratory merged later into the Prins Maurits Laboratory (TNO-PML).

Annotations are in between [ ].



After the capitulation of the Dutch Armed Forces on May 15, 1940, German visits were expected. The laboratory areas were immediately put in order; appliances were taken apart and stored away; the animals of the physiological department were killed, etc. After completing these activities, it was superficially nowhere to be seen what the nature of the activities had been.

German visits

Two or three days after the capitulation, the intervention of the Inspector of Engineers announced the visit of a German officer who, together with the Director of the Military Gas School, made a tour through the Netherlands. He aimed to become acquainted with the activities that had been carried out in the field of chemical warfare in the Netherlands.
The visit to the laboratory yielded few clues. The room in which the gas filter canisters were assembled was also visited. No word was spoken about the pre-war research in a special tube for gas masks. 

The visit to the laboratory was followed by a visit to the [Artillerie-Inrichtingen (A.I.)] Hembrug, where the storage of 1,000 kg of mustard gas [sulfur mustard] was examined. There had been a fire at a building at Hembrug where this production had taken place. Without arousing any suspicion it could be stated that as a result of the fire and in connection with accidents that occurred, all equipment was taken down and completely destroyed.

Model collection.

A few days later, this first visit was followed by a second, the purpose of which was to take possession of the model collection gas masks. Due to the absence of the A.I. leadership that day, this effort succeeded immediately. Except for the collection of civilian gas masks, the entire development course in military gas mask models was lost.


Initially, the personnel remained at war strength. But with the demobilisation of the reserve officers and the redundancy of those who were trained for this purpose, combined with the dismissal of auxiliary personnel who had only recently been employed, the strength was gradually reduced to that of before the 1939 mobilisation. In due time, Dr. van Hoogeveen and Dr. van Hoogstraten left the laboratory, while Drs. Zwikker, who worked at another department of the A.I. since 1939, was transferred back. To date, the staff consists of:

1 Chemist

1 Drs. in Physics,

1 Administrator,

3 Analysts,

1 Typist,

6 Auxiliary Personnel.

Activities after the capitulation [15 May 1940].

After the capitulation, it was important to attract other work, since little work could be expected on the terrain hitherto occupied. Various possibilities were explored but with little result. Several organisations and companies were visited. Although cooperation was promised from some sides, the situation was not yet such that a large number of work assignments were already available. For the time being, we therefore had to limit ourselves to analytical work in connection with the inspection of gradually arriving material that had been ordered before. Moreover, cancelled orders and the related administration by the laboratory are a lot of work. As a result of the reorganisation of a warehouse with samples, several sample analyses had to be carried out. In the field of gas warfare, the activities were limited to the delivery of war gases for laboratory purposes and the refilling of odour measurement installations and gas instruction boxes. Incidentally, incineration devices of English origin were received for investigation.

Technical University Delft.

In September 1940, the Technische Hogeschool (Technical University Delft) was contacted about making space and personnel available for practical education. This contact contributed greatly to the insight that it must be possible to continue to exploit the laboratory during the occupation period. It started with an analytical chemistry practical assisted by Dr. Hoogeveen. This practical was taken later taken over by Dr. v. Hoogstraten. After some time, a physics practical was added to this practical, to which Drs. Zwikker cooperated during the entire period of German occupation. The lab for analytical chemistry was later expanded to two labs. Because Dr Hoogeveen was transferred to the National Office for Chemical Products and later Dr. van Hoogstraten to the State Inspectorate for Air Protection, eventually further assistance was cancelled. Initially, all practicals were filled up to their capacity. Over time, this varied quite a bit due to the uncertain situation for the students. After May 1944, these practicals practically came to a standstill.

Liquidation of the State Enterprise.

In 1942, the laboratory management had to be changed as the A.I. Chemical Laboratory, as a State enterprise, had to be liquidated by December 31, 1942, at the latest. In connection with the possibility that the laboratory could provide valuable assistance to the National Air Protection Inspectorate, this Inspectorate had already been contacted. This contact became more solid when Dr. van Hoogstraten moved to this Inspectorate.

Pending the needed change of the entire laboratory management, the form on how the collaboration could ultimately be based was not considered yet. In the meantime, work had begun. Moreover, discussions were opened with representatives of the Dutch beer breweries about establishing a test station for the Dutch Brewing and Malting Industry in the laboratory building. These co-users could use the laboratory equipment if available. Conversely, it can be said that thanks to this possibility, new collaborations were established.

Around the middle of 1942, the situation was thus that practicals for the university were taken care of, work in the field of gas warfare was carried out on a very modest scale for the State Inspectorate and a start was made with assisting in setting up the test station for the Dutch Brewing and Malting Industry.

Change of ownership of the Chemical Laboratory to T.N.O.

With these circumstances in mind, a new administration organisation had to be found. The Central Organisation for Applied Scientific Research [T.N.O.] fitted best. This organisation had already been contacted in 1940, but for T.N.O. the situation [due to the German occupation] was still too unclear at that time to step in. But, when the liquidation of the A.I. Chemical Laboratory became acute and the Netherlands Administration took interest in finding a solution, contact was opened with T.N.O. through the Department of Finance. A plan was drawn up.
The then Commissioner for the Interests of the former Netherlands Defence Forces agreed in principle with the plans and reported on 16 July 1942:

“……, that I agree with your proposal to transfer the Chemical Laboratory in Delft of your company to the Central Organisation for Applied Scientific Research [T.N.O.]. However, the relevant German authorities need to agree as far as it concerns the alienation of war loot.
I request that you perform the required activities, and, as soon as the transfer has been effected, inform me.
About the personnel who could be transferred to the laboratory, I await your further proposals. In any case, I want to promote, as far as possible, that said personnel remain in their current circumstances, which will of course be the case, as the “T.N.O.” employment relationship could be shaped in such a way that there will be no deterioration [in work-contract].”

As the above letter shows this would require the approval of the German authorities.

This approval had to be accompanied by a financial arrangement concerning the war loot. The German authority i.c. the “Rüstungs-Inspektion Niederlande Abr. Heer II” agreed to the surrender and would await further proposals. A valuation of the war loot was necessary, which was carried out internally and was limited to the “visible goods”.’

This assessment led to the following reply from the Rüstungs-Inspektion:

Wie aus dem abschriftlich beigefügten Aktenvermerk des K.V.FR. Dr. Schwartz hervorgeht, stellt Ihr Bewertungsvorschlag vom 29.8.42 in Bezug auf das Inventar des Chemischen Laboratoriums in Delft auf der ganzen Linie eine katastrophale Unterbewertung dar. Dabei hat K.V.R. Dr. Schwartz bei der Bewertung normale Anschaffungswerte zugrunde gelegt und nicht einmal den Gesichtspunkt berücksichtigt, dass es heute überhaupt beinahe unmöglich ist, derartigen Inventar auch nicht zu höhen und höchsten Preisen zu beschaffen. Sofern der St.A.I. in Liq [Staatsbedrijf Artillerie-Inrichtingen] im Interesse der Nederlandsche Centrale Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek keinen anderen Preisvorschlag machen kann, wird diesseits voraussichtlich die entschädigungslose Enteignung und Überleitung des gesamten Inventars an ein Forschungsinstitut der deutschen Wehrmacht verfügt werden.
Gleichzeitig mit Ihren neuen Preisvorschlag wird diesseits eine Erklärung hinsichtlich der recht sonderbar anmutenden Unterbewertung erwartet.
Nach Lage der Verhältnisse kommt die Rü In NL mehr und mehr zu der bedauerlichen Feststellung dass Ihr Vertrauen zum St. A.I. in Liq., von einigen Ihrer Sacharbeiter gröblich verletzt wird.

[As appears from the memorandum of the K.V.FR. Dr Schwartz, your valuation proposal of 29-08-2042 about the inventory of the Chemical Laboratory in Delft represents a catastrophic undervaluation across the board. Dr Schwartz has set aside normal purchase values for the valuation and has not taken into account that it is now almost impossible to increase such stocks. They can only be purchased at the highest prices. If the St.A.I. [State Company Artillerie-Inrichtingen] in liquidation in the interest of the Dutch Central Organisation for Applied Scientific Research [T.N.O.] cannot make another price proposal, I will probably order the expropriation without compensation and transfer of the entire inventory to a research institute of the German Wehrmacht. Together with your new price proposal, an explanation for the rather strange-looking undervaluation is expected to be provided by me. Depending on the circumstances, the Rü In NL increasingly comes to the regrettable conclusion that its confidence in the St. A.I. in liquidation has been seriously damaged by some of your agents.]

 The valuation was of course based on the assumption that no money belonged to the Germans. A point of contention was the so-called “fixed goods by destination” which is known in Dutch law and applied to work tables, fume cupboards, ventilators, etc. The German side disputed this. Payment was also demanded for these articles. They were therefore simply regarded as movable property and declared war loot.

As far as the level of the appraisals is concerned, the following list may give an idea. The third column contains the amount for which the transfer ultimately took place. These amounts were determined during a discussion between ir. Den Hollander of the Staatsbedrijf der Artillerie-Inrichtingen and the Rüstungs-Inspektion. It is possible that a single amount is not displayed correctly, but the differences cannot be great. [f = Dutch Guilders (NLG)]

Category Valuation T.N.O./A.I. Valuation Rü. Insp. The agreed valuation
Fixed by Destination f  9.562.– f  29.700.– f  15.000.–
Equipment f   5.316.– f  18.000.– f  15.000.–
Office inventory f      750.– f    1.200.– f     1.200.–
Glassware f   1.000.– f    4.500.– f     4.050.–
Chemicals f       150.– f     1.500.– f     1.500.–
  f  16.778.– f  54.900.– f  36.750.–

About any of the figures, the following may serve as an explanation. The goods fixed by destination (work tables, fume cupboards, ventilators, etc.) had cost approx. 40,000 Dutch guilders in 1939. The actual price of the appliances could be put at about 40,000 guilders and that of the glassware at 9,200 guilders. The final agreement with the Rüstungs-Inspektion could not be concluded until early 1943. However, on December 24, 1942, the purchase agreement was signed between the State Company and T.N.O.  The business content of the agreement read:

    1. Party B (State Enterprise) hereby declares to have sold and delivered ownership to party A (T.N.O.), as party A hereby declares to have purchased from party B and accepted ownership, the briefly mentioned in point 2 goods, which are located in the building loaned by the State of the Netherlands to party B, which is located at Poortlandlaan 132-134 in Delft, insofar as these goods are not located in the parts that are used by the N.V. Nederlandsche Machinefabriek “Artillerie-Inrichtingen” and those in which the brass presses are housed. 
    2. Included in this purchase and sale are:
      A. the laboratory inventory that is fixed in and or to the building, but which can be easily removed, such as fume hoods, work tables, fixed cupboards, electric light ornaments, fans and gas and water pipe accessories.
      B. the instruments, tools, etc. present.
      C. the glassware, porcelain, etc. present.
      D. the furniture, office machines, carpeting and curtains.
      The goods mentioned under A to D are transferred in the state in which they are at present and they are known to both parties.
    3. The purchase price, amounting to Thirty thousand guilders, party A declares to pay to party B before January 15, 1943, or as much later as the written confirmation of the permission of the Rüstungsinspektion has been obtained.

Therefore, this agreement shows that the State Enterprise paid the amount in excess of the NLG 30,000.
About the takeover of the personnel, T.N.O. abided by the original agreement. Although it was by no means certain that T.N.O. every member of the staff in the long term, in connection with salary or otherwise, all were taken over. This has been of great value to the staff, often protecting them from being forced to work elsewhere.

The takeover meant that those who were in permanent government employment were fired and put on redundancy pay. The employment at T.N.O. has a completely private character, albeit the employment conditions are very similar to those that apply to government employees.

The supervision of the building.

In 1936, the building, in which the laboratory is located, was given to the State Company “Artillerie-Inrichtingen”. When this State-owned company had to be liquidated, the supervision of the building also had to change hands. As T.N.O. was the most interested party and could generate the most value for the future regarding the property of the building, the supervision of the building was also transferred to T.N.O. with effect from January 1, 1943.

It was stipulated that users in possession of room spaces assigned to them before May 1940 should remain. During the German occupation, some of these rooms became fully available to T.N.O. Around January 1944, laboratories were set up for the Institute for Fuel Economy and the Fibre Institute T.N.O. were set up in one of these rooms.

Carried off instruments.

In addition to what has already been stated above about our model collection, equipment was carried off another two times. The second time it concerned a Zeiss microscope, which had been valued by us at 20 Dutch guilders. That valuation aroused the anger of the appraiser of the Rüstungs-Inspektion. We had to send this microscope to a firm in Amsterdam, which got hold of this microscope for 35 Dutch guilders. In 1943, the third incident happened. In September 1943, we received a letter from the Rüstungs-Inspektion stating that they wanted to exercise their right of repurchase. They wished to repurchase several pieces of equipment. From the side of T.N.O., the right to repurchase was successfully fought. This did not alter the fact that, when negotiations could no longer be delayed, we carried off various equipment in February 1944. This was to prevent worse. It concerned:

1 Break balance, 1 Electrolysis agitator,
1 Calorimeter, 10 Thermometers,
1 Refractometer, 6 Porcelain mortars,
1 Ampère meter, 3 Porcelain bows,
1 Voltmeter, Some glassware.

Prices were derived from the prices agreed upon when the laboratory was handed over. The total amount was NLG 578.06. As this sum was paid by postal order, we deduced that the hunt for such equipment had a private character.

After the acquisition by T.N.O.

After January 1, 1943, the ties with every State organisation were broken. Insofar as the laboratory was previously assigned a special official task, e.g. control of the smoke-weak gunpowder stocks (unknown where they were located), supervision by the Department of Defence in connection with the Public Nuisance Act, this task was continued. The laboratory remained the adviser to the Commissariat for the interests of the former Netherlands Armed Forces, to which a financial arrangement was made by this Commissariat.

After the conversion of part of the State-owned company into the previously referred to N.V., many questions arose at this N.V. concerning patents. At the request of the Director of the N.V., also the Director of the liquidating State Company, these patent problems were handled by the laboratory. This led the author to take advantage of the current lack of assignments by to laboratory to qualify for the patent attorney exam, which was passed in 1942. Even after January 1, the laboratory remained the advisor of the N.V. In the beginning, this involved a lot of work, but in the long run, this ended for the time being.

Thanks to the involvement in the T.N.O. context, it was possible for the laboratory to be assigned activities to which other T.N.O. institutes or with T.N.O. collaborating institutes had no capability. Mentioned in this context are: nitrogen and protein determinations in grass, peat research, etc. As a result, the year 1943 gave a favourable financial outcome. Admittedly, this was less due to performing analyses for wages than to the exploitation of the laboratory spaces and the remaining part of the building.

The prospects for 1944 were no less favourable. However, the war circumstances meant that it was only possible to continue for part of the year. Soon all sorts of obstacles were so great. That meant that the work had to be stopped completely.

Looking back and into the future.

Because during the occupation all former defence business units were almost completely looted [by the Germans] – N.V. Ned. Machinefabriek Artillerie-Inrichtingen largely lost all its assets including the chemistry laboratory that we had set up there – the surrender of the laboratory must be regarded as an act of wise policy, now that this laboratory, so to speak, had gone into hiding at T.N.O. and has emerged completely unscathed from the German occupation. This is probably the only former defence department that is in this favourable position. Some instruments were indeed taken away, but there were duplicates. All special equipment, such as e.g. those for chemical and physical research of explosives and (and war gases), have been preserved. About these special research areas, the laboratory will immediately be able to resume its original task. The Central Organisation of T.N.O. had a similar vision of the future when they took over the laboratory. T.N.O. is seen here as a bundling and coordination entity of all forces and institutions that have applied scientific research as the basis of their activities.


Additional information [2023]

[1] Het Staatsbedrijf der Artillerie-Inrichtingen
[2] Van Militaire gasschool naar Nucleaire, biologische en chemische school
[3] Brand bij de Hembrug (1939)
[4] Burgerbevolkingsgasmaskers
[5] Rijksbureau voor Chemische Producten
[6] Rijksinspectie voor de Luchtbescherming
[7] ZaanWiki – Artillerie Inrichtingen (AI)
[8] Het Staatsbedrijf der Artillerie Inrichtingen – Een uitgebreide beschouwing van het bedrijf dat in de roerige jaren 1935-1945 de spil was van de Nederlandse wapen- en munitieproductie.
[9] Effectieve defensie is een kwestie van vooruitzien. 50 jaar defensieonderzoek in TNO (1997)

During the war, the ‘Poortlandlaan’ was also a hiding place for part of the Dutch pre-war defence research. In 1949, the T.N.O.-Poortlandlaan chemical laboratory was transferred by the Central Organisation TNO to the newly established National Defence Organisation TNO (RVO). With several dozen employees, it was the RVO’s second-largest laboratory at the time of the transfer. To avoid confusion with the Chemical Laboratory RVO-TNO, the transferred Poortlandlaan Chemical Laboratory was given the name Technological Laboratory RVO-TNO.