The author makes a contrasting connection between the younger students who greeted the new practice with enthusiasm and the "old guard" who held on to their beliefs in miasmas.
The author connects the ideas in this sentence by contrasting two groups: the younger students who greet the new practice with enthusiasm and the "old guard" who have clung to their belief in miasmas.
In this sentence, the author is making a contrast or juxtaposition between the attitudes of the younger students and the "old guard" regarding a new practice. The author highlights that the younger students greeted the new practice with enthusiasm, suggesting that they are open to new ideas or willing to embrace change. On the other hand, the "old guard" is mentioned to have "skated their reputations on the belief in miasmas," implying that they are resistant to change and rely on outdated beliefs or traditions to maintain their reputation. Therefore, the author is emphasizing the difference in attitudes, with the younger students being more open-minded and the "old guard" being more entrenched in their old beliefs.
