228 THE AMEKICAN MONTHLY [October, 



the circumstances, being fired each time through a heavy twilled pocket, 

 was the nearest distance at which the kind of cartridge used could pos- 

 sibly make a sijiooth, round hole. The hole becomes more jagged and 

 larger, the nearer the muzzle approached the cloth, imtil when in ac- 

 tual contact (as it was claimed by the prosecution xuas the case in the 

 shooting of Mrs. Vail) a great hole, from two to three inches in diame- 

 ter, is blown bodily through the stuft', leaving the latter torn in every 

 direction, and almost always on fire. 



These points being settled, I next examined the buckram, or heavy 

 linen stiffening. The fibres of this material gave the least evidence of 

 change under the scorching influence of the gas. There were no 

 powder marks or cavities, and the most that I could discover was a 

 slight deposit of soot on the outer side of the thread. In buckram 

 scorched by experimental discharge, the threads unravelled and picked 

 to pieces showed no structural changes. The burned ends of fibres are 

 always conical and opaque for a short distance back from the burned 

 portion. From its exceedingly hard and closely twisted nature this 

 is what we might expect. 



A piece of fine linen cambric, unstarched, scorched by the side flash 

 from the aperture between the muzzle of cylinder and the barrel of the 

 pistol, was far more strongly marked. There were no detectable struc- 

 tural changes, but the fibres were deeply burned on the exposed side, 

 sometimes down to more than half their diameter, and in a few instances 

 burned through. 



A piece of the same cambric, starched and smoothly ironed, under 

 similar circumstances, was not nearly so sevei-ely marked. 



It is, however, when we come to silk that we find the greatest and 

 most interesting structural changes produced by scorches. When held 

 close to the source of heat (the flame jet) the fibres twist and warp in 

 every direction, at points apparently fusing together and making a net- 

 work that can be compared to nothing more aptly than to the figure 

 produced by cutting little lines of slits in paper, each line of slits break- 

 ing joints with its neighbor, and then opening the paper out — after the 

 fashion of the " expanded metal " screens of the present day. At points 

 burned by partially combusted powder or other glowing matter, the 

 whole mass of fibres constituting a thread end, actually fuse together, 

 making a solid mass, from brown to black in color, and often contain- 

 ing small bubbles of gas. The fibres swell and become opaque, some- 

 times granulated. 



To sum up : 



Wool fibre becomes opaque on the side exposed to the flash, thickens 

 in diameter, warps, and frequently twists on itself. The depth of the 

 opacity is in direct ratio to the amount of heat applied. The opacity is 

 found on examination with higher powers to be due to a splitting up of 

 the cortical and a granulation of the medullary structure. In black-dyed 

 fibres the thickening and distortion are the same as in white fibres, but 

 the degree of opacity cannot be observed. 



Cotion Fibres. — These are more easily affected by a flame jet than 

 any others examined by me. They show a discoloration at the point of 

 contact with flame, merging from jet black (carbon) to a faint brown 

 through all gradations of brown. When burned through and subjected 

 to rubbing or manipulations, the end is left either square or slightly con- 



