^^40 Experiments of M.onxMvL\^ Ridolfi and others, 
that a magnetic needle might have been substituted in place of 
the unmagnetised one, during a few seconds when he left the 
apartment, yet such a supposition was completely excluded 
by the high integrity of Morichini, and of the young Italian 
Nobleman who assisted him in the experiment. 
It is not, however, on the testimony of Morichini alone that 
we are? disposed to give credit to this new property of light. 
The very same results were obtained by Dr Carpi at Rome, 
and M. Cosimo Ridolfi at Florence; and though, under a 
more northern and less serene sky, the experiment has been 
unsuccessful, yet, when we consider this difference of circum- 
stances, we cannot regard the evidence of those who have failed 
as in the least degree invalidating the evidence of those who 
have succeeded. Dr Carpi maintains,, that the temperature is a 
matter of indifference, but that the clearness and dryness of the 
air are of essential importance. M. Ridolfi exposed his 
needles to the influence of the extreme border of the violet 
ray. He magnetised some in thirty, and others in forty-five 
minutes ; and he considered the chemical rays as contributing 
to the success of the experiment. His experiments were per- 
formed under almost every variety of circumstances. He mag- 
netised the needles when the apartment was rendered very hu- 
mid ; but when the violet ray passed through a column of wa- 
ter in vapour, or when the needle itself was immersed in water, 
no effect was produced. When the violet light was transmitted 
through the thick smoke of burning sugar, the needle received 
only a very slight degree of magnetism 
M. Berard, an eminent chemist of Montpellier, repeated the 
experiment of Morichini, when he was engaged in examining 
the invisible and the deoxidating rays.: As we have not seen 
his own account of the results which he obtained, we must con- 
tent ourselves with quoting the abstract of them, given by M. 
Cuvier in his account of the labours of the Institute for 1818. 
Equally decisive results have not been obtained respecting 
the property of magnetising steel, ascribed to the violet ray by 
M. Morichini, a well-informed Roman chemist. Although 
needles exposed to this ray appeared to be magnetised in cer- 
* See BrugnatelWs Journal 1816, 5th bimeetre, or the BihUotheg^m Universdlc 
1817, tom. V. p. 1. 
