THE RUDOLF REPORT

8. EVALUATION OF CHEMICAL ANALYSESFig. 70: Picture of the door frame in disinfestation wing of building 5a. thelower, rusty hinge has developed Iron Blue under the influence of hydrogencyanide. Sample taking location of sample no. 18.underlying brick structure of such walls. Differently-baked bricks havea different tendency towards accumulation through condensation dueto their differing heat conductivity. Differing reactivity to the formationof cyanides due to differing moisture contents and temperaturesmay therefore be the cause of this effect, but also differing transportcapacities for migrating cyanide salts due to differing moisture contents.Underneath the first layer of wall plaster, only approximately 1mm thick, the material appears, by contrast, pale blue, just like the entireeast wall of the wing, which is an interior wall of the original disinfestationchamber and whose discoloration is much less intensive(samples 12 and 13).The interior walls of the same room, which were incorporated at alater time, i.e., those belonging to the hot air disinfestation chamber(see Fig. 18), exhibit, as expected, no trace of blue.The results of samples 9 and 11, and 20 and 22, resp., confirm thefirst impression. The topmost layer of plaster on the inside of the exteriorwalls has a very high cyanide concentration; underneath, the concentrationdecreases. The high cyanide concentration of Sample 11could not, however, be exactly reproduced. The results of the controlanalysis lies at only 54% of the first value. The slightly different ana-261