glowe and Jack,
You are both wrong about early .38 Spl. loadings!
Cited from "U.S. Cartridges and Their Handguns" by Charles R. Suydam, (C) 1977, pp. 172-173: "the .38 Smith & Wesson Special cartridge was first made by UMC early in 1899; cartridges were sent to Smith & Wesson for trial in May of that year. Original loads were 18.0 grains of black powder, ...... In June, 1899, the powder charge was increased to 21.5 grains:... The first smokeless loadings were made in September, 1899,....."
So, you see, the earliest .38 Special loadings were with black powder only from May to September 1899. Both black powder and smokeless loadings were produced from 1899 to, as I recall, sometime in the 1920s or '30s before finally being discontinued. Smokeless loadings were not produced "from the very beginning", and glowe's remark "I do not believe that the 38 Special was ever commercially loaded in black powder.", is equally incorrect. The cartridge was exclusively a black powder load from May to September, 1899.
The cited book is an excellent reference for anyone really interested in U.S. cartridge development. One copy of the first edition is available on E-bay if anyone is interested, only $59.95 BIN.