THE RUDOLF REPORT

GERMAR RUDOLF · THE RUDOLF REPORTsee Fig. 72. 16% H 2 SO 4 was placedin a crucible, KCN was added bymeans of a magnetic lever mechanismwith the container sealed. Themixing was performed by means ofa magnetic stirrer.The samples listed in Table 21were analyzed. The following parameterswere kept constant:• 11°C air and sample temperature;• 90% relative atmospheric humidity;• Storage of the samples for approximatelyfive weeks underthese conditions prior to initiationof the tests;• Sealing of the samples on allsides, except for one frontal surface,with paraffin 52/54 (thusfumigation on one side only)• Fumigation with 2% by volumehydrogen cyanide;• 24.75 hours fumigation time;• Storage of the samples after fumigationat room temperatureand low atmospheric humidityfor 71 days.Exceptions from these conditionsare listed in the right columnof Table 21 (p. 267). Followingfumigation, the topmost layers ofthe sealed surfaces of samples 27 to 30 were removed, and hence thesealing layer of paraffin. The additionally moistened samples 27 and30 made themselves perceptible by an intense odor of hydrogen cyanideduring storage at room temperature, in contrast to samples 28 and29 which were only moist by nature. The odor of hydrogen cyanidedisappeared suddenly upon additional moistening. In the case of the266Fig. 72: Construction drawing ofthe experimental container forthe fumigation of materialsamples with hydrogen cyanide.1: Glass cylinder2: O-sealing ring3: PVC lid and floor plate4: Gas outlet and pressuregauge5: Gas ventilation outlet6: Magnet mixer motor7: Porcelain dish with 16 Vol.%H 2 SO 4 and magnet mixer8: Spoon with KCN fixed axle,capable of tipping over magnetfrom exterior9: Sample material (here brick)10: Bolts