of winston-salem, north carolina on c-span twos book tv and on american history tv.ouncer: washington journal continues. greta: back at our table this morning, dale kimball. kimball. how do we know that we can tie this to russia? daryl: this substance is uniquely russian. this is a type of nerve agent that is very deadly. began developing it in the 1970's. they are known to have produced some of this from defectors. this is a uniquely russian substance. what is interesting is the fascination took place in salisbury, england. close tonot occur so that world-class live, we may not have known that the substance was used because what nerve agents do is they incapacitate the victim. they stop the nervous system functioning. it often produces it a heart attack at a high dose. -- it often produces a heart attack at a high dose. he survived for reasons that are not clear. clearly wanted to assassinate this double agent. the use oft expect this agent. their use is clearly prohibited. there will be consequences for russia. i think they will continue to deny it. greta: some mig

of winston-salem, north carolina on c-span twos book tv and on american history tv. announcer: washington journal continues. greta: