50 Years Ago

Learned behaviour is reported to be transmitted by injecting into untrained animals fractions or homogenates, containing RNA, from the cerebral hemispheres of trained rats ... The transfer problem is very important for the understanding of memory and learning, and we have carried out a series of experiments with rats ... Each recipient was given intraperitoneally 1 ml. of a solution containing total brain RNA extract from one donor ... A general trend is revealed ... which shows that injectees which received extracts of trained donors performed better than recipients of control brain extracts ... Our findings do not, of course, indicate whether they concern the transfer of some specific memory mechanism or simply of a certain kind of excitatory state.

From Nature 14 October 1967

100 Years Ago

Meteors of the largest type exhibit a propensity to appear in the twilight of early evening. On Monday, October 1, at 6.37 p.m., a splendid object of this class presented itself, moving slowly along an extended flight in a south to north direction ... descriptions have been received from places so wide apart as Weston-super-Mare, Somerset, and the extreme North of England ... The Rev. J. Dunn, of Weston-super-Mare, describes the fireball as very brilliant, passing just above Capella. It was visible for five seconds; the head was some ten minutes of arc in diameter, and it threw off a short, reddish tail of sparks ... Mr. T. J. Moore reports from Doncaster ... that about one minute after the object had passed a very loud explosion was heard ... Spectators agree as to the remarkable brilliancy of the object, and state that it aroused apprehension in cases where its nature was not understood.

From Nature 11 October 1917

Footnote 1