28 REPORT—1846. 
tro-magnetic rotation takes place all round each, which is in the sense of the hypo- 
thetic currents of Ampére. Prof. Grove has just pointed out to me that such an action 
had been stated by Dr. Christie, though, as far as I know, it had been referred to 
by no treatise on electro-magnetism, and that he himself had witnessed the phzeno- 
menon many times. ‘The other fact seems to be of a higher interest, since it declares, 
as it were, to the eye, what may be called the lines of chemical affinities. I shall now 
content myself by merely describing what I have been able to witness and to show to 
many scientific men, reserving for a future occasion to complete this communication 
and to dwell upon the theoretical part of the subject. Common sulphate of copper is to 
be dissolved in water, and a cylinder of soft iron dipped into it; as soon as the first 
deposit of copper has taken. place, it is easy to perceive all round the cylinder light 
films of a blue matter which are extending themselves as diverging rays from the very 
centre of the cylinder which may be thought to represent the centre of the chemical ac- 
tion. I suppose this substance to be a subsulphate of copper, and Prof. H. Rose is of 
the same opinion; but from want of time and scarcity of matter, I have not yet been 
able to submit it to analysis. During the progress of its manifestation, the nature of the 
liquid is always varying, sulphate of iron taking the place of a corresponding quantity 
of sulphate of copper. When this change has reached a certain extent, the phenome- 
non ceases to spread. It is then like to a large passion-flower, with slender stamina 
terminated by a continuous circular and opake ridge of thick anthere. Its figure, 
which is altogether independent of the nature and the form of the vessel, is very geome- 
trical. After halfan hour, more or less, this extraordinary design fades by the deposition 
of the matter at the bottom of the trough. When two cylinders are used in the same 
plate, two of the rays meet each other perpendicularly on the line of shortest distance of 
the centres. Others join in direction more and more oblique, and being totally deprived 
of the faculty of entering their relative dominions, they incurve themselves in hyperbolic 
arches. Thus a perfectly straight line is formed which cuts into two halves the line 
of shortest interval. It is scarcely necessary to add that the rays which are not to 
meet others, extend as in the first case described. With three centres situated at the 
summits of an equilateral triangle, the lines of separation intersect each other in a 
point which is at equal distance from the summits, and thence run perpendicular to the 
three sides of the triangle. The diverging rays, opposite in two directions, are much 
inflected. The whole of the figure is perfectly regular. These rays are not affected 
in their development by the magnetization of the cylinders; at least, if one observa- 
tion made on this point suffices for deciding the question. If there are but two cylin- 
ders, and if they are lifted up in the liquid by means of an appropriate horse-shoe 
magnet, it is possible to move them very slowly without any disturbance of the figure, 
and particularly without the least incurvature of the line of separation, which follow 
the cylinders backwards and forwards, as if firmly tied together. But a shock loosens 
all those particles geometrically adherent ; they fall down, and all the design vanishes. 
Summary of Researches in Electro-Physiology. By Prof. Martevucct. 
In the first place he described the experiments which prove that the development of 
electricity in living animals is a phenomenon appertaining to all organic tissues, and 
principally to muscular fibres, and that it is a necessary consequence of the chemical 
processes of nutrition. He particularly wished to prove that the development of elec- 
tricity in the muscles can never produce electric currents which circulate either in the 
muscular mass or in the nerves. It is only by a particular arrangement of the expe- 
riment that we succeed in obtaining a muscular current. 
Further, all experiments contradict the opinion of an electrical current existing in 
the nerves. M. Matteucci proved that the current said to be proper to the frog is 
on the contrary a general phenomenon which exists in all the muscles that have ten- 
dinous extremities unequally distributed, and that this current, supposed to be peculiar 
to the frog, is only a particular instance of muscular current. In the second place, 
the Professor laid before the Section his last researches on electrical fishes. He showed 
that the laws of the electrical shock of these animals are a necessary consequence of 
the development of electricity, which is produced in each cell of the electrical organ 
under the influence of the nervous power. In the third place, he showed the relation 
which exists between the electrical current and nervous power, and proved that mus- 
