It would help to specify which town information is being requested from; there are 3 towns that sound like this:
• Wiśnicz, currently known as Nowy Wiśnicz, Poland
• Wiznitz, currently known as Vizhnitsa, Ukraine
• Vishnevets, Ukraine

JRI-Poland has indexed the Jewish vital records from Nowy Wiśnicz for the entire period you have specified (and many more years), with the exception of deaths 1850-1858.

In almost all cases up through 1911 there are high resolution scanned images available of the original records.

Howard Fink
genKnowHow@...
Nowy Wiśnicz Town Coordinator
Jewish Records Indexing - Poland