86 JOURNAL OF THE 



ADULTERATED SPIRITS OF TURPENTINE. 



A CONVENIENT METHOD FOR DETECTING AND FOR ESTIMATING PETROLEUM 



IN SPIRITS OF TURPENTINE. 



BY SAMUEL J. HINSDALE. 



Put ten drops of the spirits to be examined in a (moderately 

 concave) watch glass, and float the glass on about a quart of 

 water which has a temperature of about 170° F. If the spirits 

 is pure it will evaporate and leave the glass quite dry in seven 

 minutes. If the spirits contains even five per cent, of petroleum 

 it will not have completely evaporated in that time. 



This experiment will prove the absence or presence of petro- 

 leum in the sample. 



To estimate the percentage of petroleum, weigh a watch glass 

 and put into it ten drops of the mixture, and w^eigh again. Put 

 into another glass ten drops of pure spirits of turpentine and 

 float both glasses on about a quart of water at about 170° F. 



As soon as the pure spirits has evaporated take off* the glass 

 which contained the mixture and weigh it. The difference 

 between this weighing and the weight of the glass will indicate 

 the amount of petroleum in the mixture. Knowing the weight 

 of the ten drops, the percentage can be calculated. 



A bent loop of wire is convenient to place on and remove the 

 watch glass from the water. 



The hydrometer will detect adulteration wnth benzine or 

 petroleum, but it cannot be used to estimate the amount of adul- 

 teration. 



The specific gravity of pure spirits of turpentine is about 0.865. 



Petroleum is the usual adulterant. 



Fayetteville, N. C. 



