Deciphering a mineral deed

We have an oil and gas exception in our chain of title. We are trying to find out if the deed reserves 1/16 of 100% of the oil and 50% of the gas, or 1/16 of the oil and 1/2 of the gas. The next deed in the chain from the Dirks to the next land grantee, says “excepting 1/16 of the oil and gas. Subject to previous deeds”. Any help would be greatly appreciated.

"This agreement entered into between James Dirk and Helen Dirk, his wife, of the County of Belmont and State of Ohio, parties of the first part, the grantors, and M.J. Smith party of the second part, grantee.

WITNESSTH, That the parties of the first part, in consideration of the One Dollars paid by the party of the second part , the receipt of which is acknowledged and of the agreement of the said grantee hereinafter contained do hereby grant and convey by deed of general warranty unto the party of the second part his heirs and assigns forever, the one-sixteenth ( 1/16) part of all the oil and one-half gas in place in and under, or which may be produced from the following described piece or parcel of land, together with the rights and privilege of the use of the land for oil and gas exploration and production which land is situated in the Township or District of Smith, County of Belmont and State of Ohio and bounded and described as follow, to-wit-

On the North by lands of Joseph Martin

On the East by lands of Don Mythe, Charles Golden and L.N. Smitten

On the South by lands of Fendal Lewis and H.W. Lewis

On the West by lands of Joseph Martin and Arness Waller

Containing 92 acres, more or less, but the grant aforesaid is subject to any valid lease or leases for oil and gas now on the premises, only while the said remain in force. There is also hereby granted and conveyed to the said Grantee by said grantors for the consideration aforesaid, that and in case the first well on said premises averages Fifteen Barrels of oil daily, pipe line measurement for one month after the first months producing seven hundred and fifty Dollars additional shall be paid for the grant and deed.

Dated the 18th day of May A.D. 1914