Fix #11

bitshares/account.py

@@ -47,7 +47,7 @@ class Account(BlockchainObject):
             account,
             lazy=lazy,
             full=full,
-            bitshares_instance=None
+            bitshares_instance=bitshares_instance
         )
 
     def refresh(self):

bitshares/memo.py

@@ -63,7 +63,7 @@ class Memo(object):
             PrivateKey(memo_wif),
             PublicKey(
                 self.to_account["options"]["memo_key"],
-                prefix=self.bitshares.rpc.chain_params["prefix"]
+                prefix=self.bitshares.prefix
             ),
             nonce,
             memo