This is an extremely vague question and because of this it is very difficult to answer. When you say 'foreign chemists', this could mean from a host of countries. Foreign usually means outside of the country you are in, so this question really does depend on what country you are in. It can be assumed that most scientific and chemical breakthroughs came about in Europe in the 17th, 18th and 19th centuries meaning that most prominent chemists of their time where from European countries. If you are based in The USA then they could well be described as foreign.
- One of the most famous and well-respected scientists in history was Albert Einstein, who was born in Germany. Einstein is probably one of the best-known European scientists, though not technically a chemist and his theories on relativity have made him globally renowned.
- Marie Curie was a French chemist who was born in Poland. She pioneered research in cancer treatment and notably radiotherapy treatment. Cancer care units around the world are now named after her.
- Joseph Lister was a British born surgeon who was responsible for advancements in antiseptic treatments and sterilization of instruments. His work has had a huge impact on the way medical procedures are carried out today.
- Fritz Haber was a German chemist who received the Nobel Peace Prize for his research in synthesizing Ammonia, which later was used in the creation of explosives. Although seen as a pioneer in the field of chemistry, his work was later credited for accelerating discoveries in chemical weapons.