— 118 — 



the camphor industry. When 100 kilos turpentine oil (pinene) are converted 

 into bornylchloride (so-called pinene hydrochloride) within the space of 

 one hour, 119000 calories are liberated, and it is therefore necessary to 

 employ freezing-apparatus to absorb this volume of heat in order to make 

 it possible to carry out the reaction at the required temperature (-f- 15° C). 

 When this temperature is observed the yield of bornyl chloride equals 

 100 to 110% of that of the turpentine oil employed, whereas, if freezing 

 were omitted, the maximum output would be 35%. 



Grimaldi 1 ) by means of the glacial acetic acid-sulphuric acid and the 

 acetate of mercury reactions had already detected the presence of camphene 

 in the resin-essence. The same investigator 2 ) has now also subjected 

 turpentine oil, pine tar oil and mineral oils (benzene, petroleum) to the 

 acetate of mercury test in the expectation that these distillates would 

 behave differently towards the reagent and that it might thus be possible 

 to differentiate between them. His expectation was confirmed to this 

 extent, that under certain definite conditions the three oils: turpentine oil, 

 pine tar oil and resin essence differed from each other under the acetate 

 of mercury reaction, both in respect to the colour which they assumed 

 as well as in the time required for the formation of a precipitate and in 

 the solubility of the precipitate in nitric acid. The precipitate obtained 

 with turpentine is completely soluble in the last-named acid, but those 

 from pine tar oil and resin essence only partly so. Grimaldi believes 

 that the cause of this difference is due to the different constitution of the 

 terpenes which compose the various oils, inasmuch as when pine tar oil 

 and resin essence were purified by Aschan's method 3 ) and boiled over 

 sodium a portion of the precipitate remained insoluble. The method 

 worked out for identifying turpentine oil will probably attract less interest 

 than the method for detecting the adulteration of this oil with not too 

 small proportions of the two other oils. This is carried out by bringing 

 into a flask holding about 500 cc, and provided with a cut glass stopper 

 200 cc. of the reagent (consisting of 27,5 g. acetate of mercury made up 

 with water to 110 cc, dissolved and filtered) and 4 cc. of the oil under 

 examination (which must have been previously distilled) and shaking the 

 mixture very frequently, especially during the first few hours of the test. 

 After 48 hours 160 cc. nitric acid (3 vols acid, d 1,40 and 1 vol. water) 

 is added, the whole being well shaken several times in order to induce 

 more rapid solution and left standing. Pure turpentine oils give a clear 



x ) Chem. Ztg. 33 (1909), 1157; 34(1910), 220; Report April 1910, 118. The denomination 

 "turpentine essence" used by Grimaldi to indicate resin essence is calculated to mislead and 

 to cause confusion with turpentine oil (French: essence de terebenthine). The proper name 

 of the oil is Resin-Essence, Spirit of Resin or Light Resin Oil. 



2 ) Chem. Ztg. 35 (1911), 52. 



3 ) Zeitschr. f. angew. Chem. 20 (1907), 1811. Report April 1908, 105 



