304) Chemical Analysis of true Oil of Roses. 



it afforded a most delightful odour. A single drop was sufficient 

 to fill a room for several days with a most agreeable odour of 

 roses. It congealed into a white, foliated, transparent mass 

 when exposed to a temperature of 32° Fahrenheit, but became 

 fluid again on raising the temperature to 72° Fahrenheit. Spirit 

 of wine of 0.815 sp. gr. dissolved at 65.1 Fahrenheit ^lo pavt 

 of it. A drop required for its perfect solution 8000 grains of 

 distilled water. Owing to the small quantity of the oil in my 

 possession, amounting to not more than 15 grains, it was im- 

 possible for me to separate the different substances of which it is 

 composed, in order to analyze them. I was obliged to rest 

 satisfied with obtaining die proportions of the ultimate consti- 

 tuent parts, which is as follows. Carbon 69.66, hydrogen 

 16.06, oxygen 14.29; = 100. 



The oil of roses met with in trade in Germany, is very often an 

 adulterated compound. I have about half an ounce of it, but 

 it differs in several respects from the pure oil. It congeals much 

 sooner than the genuine, and requires for its melting again a 

 higher temperature. It is only partially soluble in spirit of 

 wine, and is nearly insoluble in water. — Schweigger, SeideVs 

 Jahrhuch, H. 4, 1830. 



On the Utility qfjixing Lightning-Condnctors in Ships. By 

 W. S. Harris, Esq., Member of the Plymouth Institution. 

 Continued from page 167. 



25. jJiXPERiENCE shews that lightning-rods have no such at- 

 tractive power as that attributed to them ; and that ships are 

 equally open to atmospheric electricity, whether furnished with 

 lightning-rods or not. In proof of this position, we shall cite 

 the following cases : 



(J) His Majesty's ship Milford was struck by lightning, in 

 Hamoaze, in January 1814, and the temporary mast fixed in 

 her greatly damaged. This ship had not a lightning-conductor 

 at the time ; but there were many other ships close by, and a 

 powder magazine, all armed with this means of defence, termi- 

 nating in points : but these xoere not assailed by an explosion, 

 so that no damage whatever occurred to them. 



