Marcellus Bailey (1840 – January 16, 1921) was an American patent attorney who, with Anthony Pollok, helped prepare Alexander Graham Bell's patents for the telephone and related inventions.
John Shaw Crout (July 5, 1899 - October 31, 1987) was the Director of Engineering at Battelle Memorial Institute when, in 1944, Battelle was visited by Chester Carlson, in order to obtain support for his idea about a xerographic process.
Henriette Mertz (1898–1985) was an American patent attorney and ancient history researcher from Chicago.
 During World War II, she worked as a code-breaker for the U.S. government's cryptography department.
 She published several controversial works during the 1960s and 1970s relating to the early discovery and settlement of America.
An information disclosure statement (often abbreviated as IDS) refers to a submission of relevant background art or information to the United States Patent and Trademark Office (USPTO) by an applicant for a patent during the patent prosecution process.
 There is a duty on all patent applicants to disclose prior art or background information that may be relevant to the patentability of the applicant's invention, as established by the United States Code title 35 and related sections of 37 CFR and the Manual of Patent Examining Procedure (MPEP).
 If a patent applicant knowingly or intentionally fails to submit prior art to the USPTO, then any patent that later issues from the patent application may be declared unenforceable.
 Furthermore, the duty to submit such relevant information to the USPTO lies not only on the applicant or inventor, but also on any patent attorney or other legal staff employed by the applicant.
Octrooibureau Vriesendorp & Gaade B.V. is a Dutch patent attorney agency, founded in 1833.
 The firm was not continuously active as a patent attorney agency, however, because the Netherlands abolished patents in 1869, and did not reintroduce them until 1912.
Alan H. MacPherson (August 10, 1934 - December 8, 2008, Laguna Beach, California, United States) was an American patent attorney who pioneered the "clean room" defense.
Chester Floyd Carlson (February 8, 1906 – September 19, 1968) was an American physicist, inventor, and patent attorney born in Seattle, Washington.
Harold Leidner (31 January 1916 – 13 August 2008) was an American patent attorney and amateur scholar of early Christianity.
Anthony Pollok (1829 – July 4, 1898) was an American patent attorney who, with Marcellus Bailey, helped prepare Alexander Graham Bell's patents for the telephone and related inventions.
Dennis David Crouch (born April 30, 1975 in Columbia, South Carolina) is an American patent attorney who worked for McDonnell Boehnen Hulbert & Berghoff LLP (MBHB) in Chicago, Illinois, until 2007.
 In 2007, he accepted a post of associate professor at the University of Missouri School of Law in Columbia, Missouri.

Question: What American patent attorney visited John Shaw Crout in 1944?
Answer: Chester Carlson