The section of chapter 18 you refer to is from Mina Harkers’s journal. It records a meeting between an eclectic mix of people seeking to end Dracula’s tyranny. Van Helsing, the Dutch academic and vampire expert, launches into a lengthy lecture on the powers and limitations of vampires to ensure that all are aware of the dangers and possibilities they face in their efforts to kill Dracula.
According to Van Helsing, vampires have a lengthy list of lethal attributes that he claims he knows based on his understanding of “traditions and superstitions.” Count Dracula is immortal and “cannot die by mere passing of the time” but needs to feed regularly or else he “cannot flourish.” Vampires can “transform himself into a wolf,” can “be as a bat” and even evaporate into “mist”. Count Dracula can also “see in the dark” and is able to “slip through a hairbreadth space.” This is a formidable list of attributes for the aspiring vampire hunter!
However, Van Helsing also catalogs a variety of weaknesses that will help them defeat Count Dracula and even asserts that the vampire is “even more prisoner than the slave of the galley, than the madman in his cell.” These weaknesses focus on limits to Dracula’s freedom, such as the fact that he can only transform into animals or cross running water at certain times. Van Helsing also outlines Dracula’s vulnerabilities to garlic, wild roses, and crucifixes. Armed with the knowledge of Count Dracula’s strengths and limitations, the small band will begin to plan their attack.