Adulterated Olive Oil

Tt is a matter of considerable difílculi.y t.o discover whotlier cotton-seed oil lias been used to adultérale olive oil. Benjamin Nickels thinks thatj.be spectroscope might be turned to account in detecting its presence. This is bis reasouing : Vhen examined'with a good direct-vision instrument, puro oíive oil presents a deop shadowing of the blue or violet ray, with an indistinct line In the green and a strong band in the red, and cotton-seed oil, while giving exact.ly the same sort of blue or violet ray, shows no lino in the green or band in the red. If, thereiöre, a stratum of pure olive oil and a liko one of the pure oil in admixture with cotton-seed oil be severally exaniined and compared, there will be no difference observable so far as the shadowiutc of the blue aud violet is concerned ; but the adulterated sample will give hardly any line in the green, and the strong band in the red will bo fonnd to have not nearly anything of the depth and intensity prescnled by the pure or standard stratum. A dilution of 25 percent, he says,may thua be determinad. This method is not advaneed as absolute proof that there had been cotton-seed oil put in an adulterated sample oí olive oil, but only as affording strong presumptivo evidence that such had been the fact.