[3011] “Calefiat.”

[3012] Snow-water is pernicious in a very high degree, being the fruitful source of goitre and cretinism.

[3013] See B. xvii. c. 44, and B. xviii. c. 68.

[3014] This is somewhat similar to what is said of the putrefaction and purification of Thames water, on a voyage.

[3015] “Inutilis alvo duritia faucibusque.” The passage is probably corrupt.

[3016] See B. vi. c. 27.

[3017] Or “mud”—“limus.” All rivers of necessity have it, in a greater or less degree.

[3018] On the contrary, the more the mud and slime, the more numerous the eels.

[3019] “Tænias.”

[3020] Waters, probably, impregnated with mineral alkali. As to the “nitrum” of Pliny, see c. 46 of this Book.