Solution 198 is one of the few documented serums created by Morytanian pharmaceutical researcher Herbi Flax. 198 was one of Herbi Flax's many attempts to cure the Sanguinesti Affliction, which plagued his hometown of Mort'ton and reduced its inhabitants to savage animal-like Afflicted.

198 differed little from Solution 194, Herbi Flax's first serum to successfully suppress the effects of the disease, although only for a short time. Serum 198 contained harralander, marrentill, and ashes, as well as an additional sprig of snake weed. The snake weed, however, served only to suppress the potion's ability, reducing the amount of time for which it would weaken the disease. It was subsequently scrapped by Herbi Flax, and only recently was it rediscovered.