AGREEMENT TO JOINTLY FILE SCHEDULE 13D

Exhibit 99.1

AGREEMENT
TO JOINTLY FILE SCHEDULE 13D

The undersigned hereby agree to jointly prepare and file with regulatory authorities a Schedule 13D and any future amendments thereto reporting each of the undersigned’s ownership of securities of O.I. Corporation and hereby affirm that such Schedule 13D is being filed on behalf of each of the undersigned.

Dated: April 7, 0000	XXXXXX XXXXXX PARTNERS, L.P.
	By:	FARNAM STREET CAPITAL, INC.,
		General Partner
	By:	/s/ Xxxxxxx X. Xxxxxxxx
		Xxxxxxx X. Xxxxxxxx,
		Chief Executive Officer
	By:	/s/ Xxxxx X. Xxxx
		Xxxxx X. Xxxx,
		President

/s/ Xxxxxxx X. Xxxxxxxx  

Xxxxxxx X. Xxxxxxxx 

/s/ Xxxxx X. Xxxx  

Xxxxx X. Xxxx