The fat from Liquid melts solidifies 1^o 36°-46° 41°-? 2^o 39°-41° 37°-35.5° 4^o[6] 59°-62° 40.5°-35° 5^o 62°-66° 58°-53° 6^o 53°-56° 41°-? The melting point of liquid 2^o, does not accord with that above stated, but I note the experiments as they were observed, merely mentioning that I observed carefully, and am not conscious of having made an error. The above points seem vague, but it was impossible to fix a point definitely, as a cloudiness persisted up to the highest degree stated, so I prefer to give the limits of certainty. In 1^o and 6^o the solidifying points, 41°, were taken when the liquid in the capillary tubes seemed to become solid, but it remained translucent for a long time below this point, and 6^o only became opaque (and that gradually) when suffered to stand in the air. We are reminded here of Duffy’s observations upon certain isomeric transformations of the fats, (Quar. Jour. Ch. Sec. V. 197.) He noticed that stearine heated 1° above its point of solidification, became transparent, but soon after resumed its opacity; and Heintz made a similar observation. Duffy attributes this to an isomeric transformation of the fat by the heat; but it seems to me simpler until an isomerism be more distinctly proven, to assume a mixture of fats, which unite to form a definite compound under the circumstances, and which has the above mentioned property.[7] Heintz’s researches on the fats should make us look with suspicion upon fats as pure, that are only purified by crystallization. Duffy’s remarks were made upon the glycerine compounds of the fatty acids; it appears from the above examination of the liquids 1^o and 6^o, as if something similar took place with the fatty acids themselves, although, with one or two exceptions, in other determinations of melting points noted in this article, I have not observed the same phenomenon of transparency.