The peculiar difficulties of administering any form of intravenous therapy to small infants are well known. The median longitudinal sinus has proved most valuable as a route for giving fluids intravenously, or for transfusion, but, occasionally, attempts to administer arsphenamin and neo-arsphenamin intrasinusly have been attended with fatal results. At times, the superficial veins of the scalp are prominent and may be utilized, but often the external jugulars are the only veins available, and at times even these are not visible. It is often difficult, except for those who have had much practice, to make a clean puncture into a jugular vein which is covered by skin, fascia, and platysma muscle. As a result, various attempts have been made to prepare arsenicals in a form suitable for subcutaneous, intramuscular and rectal administration. Neo-arsphenamin, specially neutralized for intramuscular injection, can now be obtained, but its use is attended by the frequent