 Why is Macklin's reaction to the shot alarming?
But Macklin is exactly what we need for a quick, dramatic test. "When we prove our results that should be of enough practical value for anyone. No one knew whether his Theory of Spatium was correct or not because no one had yet been able to frame an argument with it. The government took up a lot of his time using him as the symbol of the Ideal Scientist to help recruit Science and Engineering Cadets. "Actually, Doctor, we haven't the right to ask this of a man of your importance. "Doctor, we understand you have severe headaches," Mitchell said. "No, Harold, it isn't," Macklin admitted. "I would have said the common cold," Macklin replied, "but I suppose from what you have said you mean headaches." "Aspirins would still be used to reduce fever and relieve muscular pains," Mitchell said. "There are a number of different causes for headaches—nervous strain, fatigue, physical diseases from kidney complaints to tumors, over-indulgence—but there is one effect of all of this, the one real cause of headaches," Mitchell announced. "The pressure effect caused by pituitrin in the brain," Mitchell said eagerly. "The virus," Ferris explained, "can easily be localized and stabilized. A colony of virus in the brain cells will relax the cerebral vessels—and only the cerebral vessels—so that the cerebrospinal fluid doesn't create pressure in the cavities of the brain."
 The shot has somehow removed his intelligence.
 He's acting as if he took a narcotic, enough that Mrs. Macklin suspects that they gave him heroin?  He's much too happy, as observed by Sidney. He's inexplicably healthy and too adjusted.  He seems unbothered by it, despite the fact that it should have changed his life.  The shot has somehow removed his intelligence.