Eiven sighed internally as the Mousian seemed to understand and carry out her orders. A lack of reaction from Kurusu, on the other hand seemed worse than being in trouble for over-stepping. Then again, with how conservative she seemed with words, the cadet began to wonder if this was more or less what he would need to get used to for this mission.
Offering another bow to the Chui, Eiven exited to go about carrying out his own orders, closing the door on his way out. Working out the precise constituent compounds and elements found in another being's standard breathing gas is usually rather difficult to work out without an analysis of their homeworld's atmosphere, walking onto one of their ships and testing the gasses present, or experimenting with various mixtures on a hopefully standard subject. There was also using the exhaled gasses of a subject and reverse engineering, hoping that you are assuming what form of respiration they are using.
Unfortunately those options all required something they did not have or putting their guest through stressful and morally dubious tests. However, with Kata'nova being able to deal with Yamataian standard, it was really down to possible trace gasses - another test that could end up dubious morally. That ended up leaving trying to talk to the girl as the only appropriate method; but in order to do that, common knowledge and language was required. Another dead end?
Sunflower's notes did suggest that Kata'nova was young, but how young, the doctor wondered. If she were old enough to possibly have some science classes, it was possible (though remote) that she may have learned a thing or two. If their guest had actually some knowledge of basic chemistry, then there would be a common language they could use. It required her to have a certain level of understanding; however at this point there was little else to go on. Eiven had to try something, and this would be the least invasive method available to him for a while.
Of course, he did have in the back of his mind that this may have been just busy work to get him out of Kurusu's hair. The surfacing though caused the old man to shake his head as he also remembered that he need to keep in mind how appropriate it was to question orders too much. In the end Eiven let out a sigh on his way through the corridors before asking Hakken about where Josea and Kata'nova were.