STATE AGRICULTURAL SOCIETY. 467 



stage of human intelligence. Be that as it may, the beneficial effect that 

 olive oil has, over human organism, cannot be disputed. 



Originally only eaten where it was made, since the communication 

 between all countries has become so much easier, this article of food is uni- 

 versally used. The most important thing is to get it pure. Unfortunately, 

 on account of the cheapness of oils made from seeds and nuts of different 

 kinds, commerce has adulterated olive oil as it has so many other articles. 

 Oils made of peanuts, sesame, cotton, and poppy seeds, are sold by millions 

 of kilogrammes under the name of olive oil. 



This unwholesome adulteration, which can create the most serious dis- 

 orders on the digestive organs, should be carefully avoided by persons who 

 have any regard for their health. 



Mechanics refuse seed oils because of their dryness, as they gum up the 

 machinery instead of greasing it and keeping it clean. It is just as im- 

 portant that the machinery of the human body should rebel against such 

 oils. "We ought to be familiar with the methods of extracting oil from all 

 oleaginous substances, being so necessary to different industries. But all 

 the table oil should give the preference to that made from a tree that the 

 Almighty saved from the destruction of the Deluge and a branch of which 

 the dove carried to Noah as a sign of forgiveness. 



Article XI. — The Adulteration of Olive Oil. 



I have copied from a paper read before the Liverpool Chemists' Associa- 

 tion, by Michael Conroy, F.C.S., the same published in the " Pharmaceuti- 

 cal Journal," as follows: 



The favorite method proposed by M. Poutet, consists in heating up the oil with one 

 twelfth of its weight of solution of nitrate of mercury. The nitrous acid or nitric perox- 

 ide evolved from this, converts the oleine of olive oil into elaidin, causing the olive oil, if 

 pure, to become solid in a couple of hours, while the drying oils remain liquid. It will be 

 seen from this that olive oil adulterated with any of the drying oils will not set as hard nor 

 as quickly as genuine olive oil, and that the consistency to which the sample sets, and the 

 time occupied in setting, somewhat roughly indicate the amount of adulteration. A mod- 

 ification of this process is to use nitric acid instead of the solution of nitrate of mercury, 

 and I believe that this plan is practiced by many oil merchants. The modus operandi is 

 to mix one half a fluid drachm of strong nitric acid with about five fluid drachms of the 

 oil in a bottle of one fluid ounce capacity, and to shake up briskly, and put in a cool place 

 for a few hours, when the color and consistency are noted. The results are somewhat 

 similar to those obtained by the nitrate of mercury test. These two tests are, in my opinion, 

 the best published; but they are not satisfactory, inasmuch as it is extremely difficult to 

 judge of the consistency of the results obtained, and, so far as my experience goes, they 

 are useless for samples containing less than ten or flfteen per cent of seed oils. 



The plan which I recommend as more suitable for the purpose is based on an improved 

 method of applying this last test; but instead of being guided by the consistency, I am 

 guided by the color produced. The test is applied as follows : mix thoroughly one part of 

 strong nitric acid (sp. gr. 1.42) with nine parts of the oil to be tested, and pour the mixture 

 into a white porcelain dish capable of holding at least ten times the quantity. Apply heat 

 gently, until the action between the acid and the oil is fairly set up, then remove the 

 source of heat and stir well with a glass rod until the action is over. 



Pure olive oil, thus treated and allowed to cool, sets into a pale straw-colored hard mass 

 in an hour or two, while cotton seed and other seed oils assume a deep orange red color, 

 and do not set like olive oil. 



In hot weather it is necessary to artificially cool the sample, so as to promote the setting ; 

 hut. to a practiced eye, the setting is quite unnecessary, thecolor being sufficiently distinct 

 without. 



It will be seen that the delicacy of this test depends upon the great contrast in color 

 exhibited hetween genuine olive and seed oils, when operated on as described, so that an 

 admixture of 5 per cent of any seed oil with olive oil is readily detected. Another impor- 

 tant feature in this, and possessed by no other test, is the accuracy with winch the approx- 

 imate amount of admixture may be ascertained; and to practically show this feature, 1 

 have on the table a sample of genuine olive oil, and one of cotton-seed, and seven other 

 samples, containing respectively 5, 10, 15,20,30, 40, and 50 per cent of cotton-seed oil, which 

 have been treated by this method, and I venture to say that not one will experience any 

 difficulty in picking nut the various samples, the gradation in color being so uniform , 

 and I may also add that it is constant. It, therefore, follows that if an oil be found to set 



