104 Dr. Penny on a Specimen of Artificial Asbestus. 



In thickness these fibres vary from j^^^ to g^j^ part of an inch. 

 The twists or turns in a fibre of cotton are from 300 to 800 in an inch. 

 D. Fig. 1. Fibres of raw flax before spinning. 



Fig. 2. Fibres of unravelled thread of manufactured flax. 



The elementary fibres of flax are also transparent tubes, cylindrical, 

 and articulated, or jointed like a cane. This latter structure is only 

 observable by the aid of an excellent instrument. These fibres vary 

 in thickness from jjuo ^^ Woo P^^^ ^^ ^^ i^^^- 



XXIX. — On a Specimen of Artificial Asbestus. 



By F. Penny, Ph. D., Professor of Chemistry in the Andersonian 



University. 



For a specimen of this substance, I am indebted to Mr. William 

 Murray of Monkland ; and, for a very accurate analysis of it, to his 

 son, Mr. Francis Murray. 



It was found in a Blast Furnace, embedded in the mass of matter 

 which had collected at the bottom of the furnace in the course of 2| 

 years, and which is technically called the hearth ; it was in a cavity, 

 about 8 inches below the level on which the liquid metal rested, and 

 was interspersed with distinct and beautiful crystals of Titanium. 



In all its general characters, this substance corresponds with As- 

 bestus. It is colourless, inodorous, and tasteless — and occurs in small 

 masses, composed of extremely minute filaments or fibres, cohering 

 longitudinally together. These fibres are very easily detached from 

 each other — and are flexible, though not so much so as the common 

 Asbestus. They have a silky lustre, and are unattacked by sulphuric, 

 nitric, or muriatic acid. They remain unchanged in the flame of a 

 spirit lamp, and are difficultly fusible even with the blowpipe. 



A preliminary examination having been made to ascertain the 

 ingredients contained in the substance, 10 grains of the longest and 

 cleanest of the fibres were selected for analysis. This was the largest 

 quantity that could be obtained free from adventitious matter. The 

 process adopted was the one usually recommended for the analysis of 

 insoluble siliceous minerals. The following are the results per cent. : — 



Silica, 72-5 



Alumina, 9*0 



Protoxide Manganese, . . 13*2 



Magnesia, 2*0 



Lime, 1-58 



Iron, 2.65 



100-93 



On comparing the above with the analyses that have been given 

 of the several varieties of Asbestus, we r emark, that the artificial 



