Ruscovitch - forger and criminal apologist

Found in a thriller from  the Donald Rudd collection of detective fiction, this preface to The Poison and the Root (Jarrolds, UK 1950) by Richard Savage. It is a sort of apologia or plea for the criminal by one G. Ruscovitch, 'professional forger'. I had thought this person was fictitious or possibly a character in the book (which is not about forgery) but in fact there was a forger of this name. He is mentioned by Havelock Ellis in The Criminal (1890) and appears to have flourished in the mid 19th Century. He may also have been a murderer but Ellis describes him thus:
'...a prince among forgers, the accomplished student of science, the perfect master of half-a-dozen languages..' He then quotes the same piece as Savage. Possibly this was spoken from the dock in mitigation:

 Too often it is forgotten that criminals are members of society. These bodies, sometimes abandoned by all except the satellites charged to guard them, are not all opaque; some of them are diaphanous and transparent. The vulgar sand that you tread underfoot becomes crystal when it has passed through the furnace. The dregs may become useful if you know how to employ them; to tread them underfoot with indifference and without thought is to undermine the foundations of society and fill it with volcanoes. The man who has not visited the caverns, can he know the mountains well? The lower strata, for being situated deeper and farther from the light, are less important than the external crust? There are deformities and diseases among us to make one shudder; but since when has horror forbidden study, and the disease driven away the physician?