199. Filling in proxy where creditor or partner is blind or incapable.

The proxy of a creditor or a partner, who is blind or incapable of writing, may be accepted if such creditor or partner has attached his signature or mark thereto in the presence of a witness who shall add to his signature his description and address:

Provided that all insertions in the proxy are in the handwriting of the witness and such witness shall have certified at the foot of the proxy that all such insertions have been made by him at the request and in the presence of the creditor or partner before he attached his signature or mark.