If one was to record a birth in Torpichen Parish in Linlithgowshire 1730 to 1740
bearing in mind the counties have possibly changed sum what and the parish church was not constructed till 1756 were would one take there children for a baptism. I am thinking possibly St Cuthberts Carnoge Edinburgh sum 25 miles away. Can anybody assist with local knowledge.
Ellecat
There was no need to take a child for baptism all the way to Edinburgh.
First, there was the Preceptory church in Torphichen. A church was built there in the late 12th century, and remodelled in the 15th century. According to
The Buildings of Scotland,
"The choir and nave .... have disappeared almost completely, although the nave survived as the parish church until it was replaced in 1756 by the present building". So there was a kirk in the parish before 1756. (A Church of Scotland parish in the 18th century without some sort of kirk is quite unthinkable.)
There was also a Associate Presbytery kirk nearby at Craigmailling in the mid-18th century. The Associate Presbytery was one of the many splinter groups that split off from the Church of Scotland.
Second, baptisms did not necessarily take place in the kirk. It was quite common for a child to be baptised in its parents' home. I have several records from 18th century parish registers that actually state that this was the case. (The practice survived until the 20th century, and for all I know may still occur; I myself was baptised in my parents' house, not in the kirk.)
The counties, and any changes made to their boundaries, would have no bearing whatsoever on where a child was baptised. The parish was the basic and significant unit. I don't think there were any significant county boundary changes in the early 18th century, but in any case, Torphichen is adjacent to other parishes that were and are in West Lothian, and would not have been directly affected by any such change.
Even if there had not been a church in the parish of Torphichen at the time, and even if the parents had been determined to have their child baptised in a kirk building, there are plenty of kirks much closer than St Cuthberts or Canongate in Edinburgh. Bathgate and Linlithgow, for instance, are only a few miles away.
I recommend reading the Statistical Account at
http://stataccscot.edina.ac.uk/static/statacc/dist/viewer/osa-vol4-Parish_record_for_Torphichen_in_the_county_of_Linlithgow_in_volume_4_of_account_1/ -this dates from the late 18th century, but does give some idea of what the parish was like then.