A fruitful source of unpleasant circumstances is the questionable custom of telephoning prescriptions. It is sometimes unavoidable, but should be done only when absolutely necessary. In case of error from any cause the burden of proof is on the prescriber to establish the fact that he really dictated what he claims. When it is positively necessary to telephone a prescription it should be first written just as if to be delivered in person; then with this before him the prescriber should, after ascertaining that he is speaking to a prescription clerk, read it off carefully and slowly enough to admit of it being taken down in full; then the clerk should be asked to read what he has written, which the prescriber should recheck from the original. He should then either send by hand or mail, at once, the written prescription marked original of prescription phoned. The druggist should use this to replace the copy which he had filled and filed. The doctor as usual retains his carbon copy.