THE recent note “Aspergillin: a Name Misapplied to Several Different Antibiotics”, in which Tobie1 deprecates the practice of assigning names to antibiotics without due consultation of the literature, prompts me to point out, for its historical interest, that even penicillin has not escaped such a duplication in naming. I refer to the use of the name 'penicillin' by Palei and Osuicheva2 in 1936 to designate a thermostable substance isolated from Penicillium luteum purpurogenum, which was unfavourable to the production of citric acid by Aspergillus niger. This was seven years after the first use of the term by Fleming3 in his now famous paper. The oversight is probably due in part to the vagaries of indexing. The name âpenicillinâ did not appear in Chemisches Zentralblatt until 1934, or in the British abstracts until 1933; it can, however, be found in the 1929 Chemical Abstracts and the Biological Abstracts for 1930. This serves as another warning against too much reliance on a single abstracting source.