On 5 February, an MI5 officer sent the tablets to Lord Rothschild of B1C who was in charge of the Explosives and Sabotage section. Rothschild forwarded the tablets to the National Institute for Medical Research in Hampstead, London where they were tested. Later, on 25 April, 1941, the tablets (slightly reduced in number) were sent to the Scientific section of the General Post Office for additional testing by H.L. Smith esq.
Group 1 Tablets
The first set of tablets were contained within a small aluminium screw-capped tube (3.6 cm long and 1.1 cm in diameter). The tube held 25 small white tablets and 2 slightly larger, heavier white tablets cross-marked to facilitate partition into quarters. The February tests concluded that the tablets were a cerebral stimulant similar to Benzedrine, which could be used to keep someone awake. The tablets had been ground up, diluted in water and injected into mice. The mice went into a state of excitement for several hours, a reaction that was similar to what happened when they were injected with Methedrine hydrochloride. Further tests indicated that the tablets were N-methylbenzedrine. The April tests concluded that the the tablets were mostly sugar but included a non-alkaloid substance such as strychine, none of which would be useful in keeping one awake.
|Tube of Pervitin circa 1940|
Group 2 Tablets
The second group of tablets were contained within a torn wrapper with red printing (W.S.P.XI ) and included three white tablets and a portion of a fourth. Both the February and April tests concluded that these tablets contained codeine and phosphate and could be used for coughs.
Jakobs said that one set of tablets was codeine, a cough cure. Codeine phosphate is an opioid and a mild pain killer. It can also be used as a cough suppressant and to treat diarrhoea.
Group 3 Tablets
The third group of tablets were contained within a wrapper of grease-proof paper with black printing (V.Z.). The five grey tablets were of obviously heterogeneous composition. Both the February and April tests concluded that the tablets contained sugar, ammonium chloride and a vegetable extract (possibly liquorice)--and would be useful for coughs.
|Packet of Acedicon ("Half a tablet of Acedicon is enough|
even for a strong cough").
Conclusion of Tests
The scientists concluded that none of the tablets contained a secret writing compound and, in fact, contained too much sugar and starch to make them suitable for secret writing.
It turned out that Jakobs was carrying genuine medicine which would not be used for secret writing.
National Archives, Security Service files - Josef Jakobs - KV 2/24, KV 2/25.