Prof. Moll on the inflammation of Phosphorus. 141 



from the observations of MM. Engelhardt and Parrot, that it 

 is found in interlaced strata in the argillaceous schistus. There 

 have been brought to me pieces of granite and gneiss detached 

 from a rock near the source of the Malka. According to the 

 information I have obtained respecting the position of this gra- 

 nite, it occupies all the bottom of the vallies, never rising to a 

 great height, and is co-ordinate with the argillaceous schistus. 

 I have been assured that the black trachyte of the central chain 

 has been seen expanded over several of the beds of granite 

 which are met with at the foot of Elbrouz, while ascending 

 the river Malka. 



The granite which I have met with in the bed of the 

 Malka is composed of common white feldspar, with a little 

 quartz and silvery mica. The mica is disseminated in it in la- 

 minae pretty large and distinct, which gives to this granite the 

 appearance of gneiss. — See our last Number, page 351. 



A rt. XV. — Historical Notice respecting the Inflammation of 

 Phosphorus in Vacuo. In a Letter to the Editor by Pro- 

 fessor Moll. 



My Dear Doctor, Utrecht, 26th May 1831. 



There is a statement in one of the last numbers of your Jour- 

 nal which, if not altogether erroneous, is certainly at any rate 

 not quite correct. I hope you will excuse me if I attempt to 

 set you right. It concerns the combustion of phosphorus in 

 vacuo, or as you express it more justly, in No. 8, p. 370, of 

 your Journal, in a partial vacuum. That experiment is attri- 

 buted by many to a countryman of mine, of the name of Van 

 Bemmelen, who by a misnomer in English and French peri- 

 odicals has been sometimes called Van Bemmcle.cr. That wor- 

 thy gentleman, since deceased, cannot claim by any means the 

 honour of the invention of this very singular experiment. 

 This honour belongs entirely to my venerable and celebrated 

 friend Dr Van Marum, who as far back as 1794, observed this 

 curious phenomenon'. He published his experiments as early 

 as 1797 in a Dutch collection of chemical tracts, called Kastc- 

 leyn, Chemische Oefeningen, vol. iii. p. 249- Soon after lie gave 

 an account of them in French, in the Description dc quclqucs 



