120 Drs. Blytb and Hofmann on Siyrole. 



t\\e mixture must be several times distilled at a low tempera- 

 ture, never reaching the boiling-point. What passes over is a 

 colourless fluid, and consists of dracyle, with a small quantity of 

 draconyle; the solid residue in the retort is entirely draconyle. 



To free the dracyle from the draconyle, '' which passes over 

 dissolved in the vapour of the former ^^ it must, acccording to 

 Glenard and Boudault, be several times distilled over hydrate 

 of potash. The potash appears here to form no combination 

 with the draconyle, " hut only to modify it in such a way that it 

 is no longer soluble in dracyle." The draconyle remaining in 

 the retort is to be washed with alcohol to remove the dracyle 

 and then heated to 150° C, by which the last traces of dracyle 

 are driven off. 



Pure draconyle is, according to these chemists, a colourless 

 mass of a shining appearance; insoluble in water, alcohol, 

 aether and potash-ley, but soluble by heat in fat and aethereal 

 oils. 



Draconyle is not volatile, but by aid of another carbo-hydrogen 

 it can he distilled. (II n'est point volatile ; toutefois, il peut i 

 distiller a la faveur d'un autre hydrogene carbone). 



From the analysis of Glenard and Boudault, draconyle con- 

 tains two equivalents of carbon to one of hydrogen. The 

 formula found for the substance obtained by the action of ni- 

 tric acid on draconyle, and for which they proposed the name 

 nitrodraconyle, was Cj4 Hg NO4. This gives for draconyle 

 Ci4 H7. That substance sealed up in a tube and heated to a 

 high temperature is converted into a yellow fluid, which boils 

 at 140° C, and has the same composition as draconyle itself. 

 Thus far are the details given by Glenard and Boudault. On 

 comparing the results of these chemists witii ours, it is at once 

 seen ihsiimetastyrote and draconyle are identical. A satisfactory 

 explanation is immediately found for some things in their me- 

 moir otherwise incomprehensible. We cannot, for instance, 

 understand how a body with the properties given it, and totally 

 devoid of volatility, can distil by the aid of another carbo-hy- 

 drogen. In boracic acid, indeed, we possess a body in itself 

 completely fixed, but which volatilizes in not inconsiderable 

 quantities with the vapour of boiling water; still this quantity 

 is but a trace in comparison with the amount of the watery 

 vapour. Our experiments however explain quite easily this 

 difficulty. Draconyle [nietastyrole) exists in the corresponding 

 "product of the distillation of dragon's blood, not as such, but in the 

 form of siyrole. After the distillation only is this styrole changed 

 into metastyrole (draconyle). It is not easily understood why 

 the mixture must be repeatedly distilled to obtain draconyle, 

 and why the distilled dracyle obstinately retains a small por- 



