1891.] MICROSCOPICAL JOURNAL. 227 



forward over a stage prepared for the purpose over which I had 

 mounted the tube of my stand, armed with a two-inch eye-piece and a 

 tWo-inch objective. The " stage" was simply a wedge-sliaped block 

 of wood eight inches long, three inches high, and four inches wide at 

 the bottom. The width narrowed toward the top to one inch and was 

 then smoothly rounded off. The bottom was grooved lengthwise with 

 an ordinary grooving plane. This block sat on a plane board eight 

 inches wide and sixteen inches long, to which was bradded, down the 

 centre, a tongue which fitted into the groove on the bottom of the 

 block. The ''stand" consisted of a percolator supporter, with an 

 arm bearing a wooden clamp which held the tube-carrier sufficiently 

 firm for my purpose. Adjustment was made as in the old Nachet 

 stands, by sliding the tube carrying the lenses up or down with a slight 

 rotary motion. Finer adjustment was obtained by touching the arm 

 with the finger. 



On examining the surfiice of the stufi' by a strong direct light, I had 

 no difficulty in finding pits in the material, in which, in many instances, 

 I found unburned or partially burned grains of powder. The ends of 

 the thread plainly showed charring, and presented the same general 

 appearances, when withdrawn and examined separately, as those 

 already described in the cases of wool and cotton. The bit of chin- 

 chilla now gave place to the coat itself, and with considerable difficulty 

 I went over the whole denuded surface around the bullet-hole, hunting 

 for grains of imbedded powder. Cavities where they had been were 

 plenty, but the grains themselves had long since been rubbed or shaken 

 out. Finally, however, my search was rewarded by finding two cavi- 

 ties close together, each of which contained a grain of powder. With 

 a pair of delicate forceps I removed a couple of the cut threads be- 

 tween these two cavities and examined them separately, after tearing 

 them out to get at the fibre. They were cotton, and very strongly 

 charred. 



I was now in a position to swear most positively that the whole of 

 this denuded area was due to char, or scorch, or burn, from the dis- 

 charge of a fire-arm. I say the ivhole of the area, and emphasize it, 

 because thereon hangs one of the most important points of the defence. 



In any series of experiments where the same weapon and the same 

 charge are used, each time the area of the scorch is in direct ratio to 

 the distance of the muzzle of the weapon from the surface scorched. 

 This may be accepted as an axiom ; and, as a corollary, we may add 

 thai the depth of the scorch and penetration of the powder will be in- 

 verse ratio to the said distance. 



These facts furnish us with an accurate scale by means of which, 

 having a similar weapon and a similar cartridge, we may determine, 

 within a margin of an inch, the exact distance from any powder-burned 

 surface at which a shot was delivered. 



In the present instance, experiment proved that the muzzle of the 

 weapon was not more than eleven nor less than nine inches from the 

 point of exit. This was corroborated in a singular manner by the char- 

 acter of the hole made by the ball as it left the overcoat. It was, as I 

 have stated, a smooth, round hole, about one-quarter of an inch in di- 

 ameter. By actual experiment, many, many times repeated, we sub- 

 sequently proved that eight inches from the muzzle of the pistol, under 



