by preventing contagion, for at a certain age the
disposition toward this disease is so great that the child will
originate it. He says: "Whooping cough is a nervous disease of immature
life, due immediately, like nervous asthma, to a morbid exaltation of
sensibility of the bronchial mucous membrane. Although possible in a
modified form at all ages, it has its period of special liability and
full development simultaneously with that time of life when the nervous
system is irritable and the mechanism of respiration diaphragmatic. A
child of the proper age with catarrh and cough is thus on the very brink
of whooping cough. A large proportion of such children will develop the
disease for themselves upon casual provocation, all contagion and all
epidemic influence apart." Therefore he does not think contagion plays
the important part generally supposed, and the assumption of a specific
morbid poison is in his opinion entirely gratuitous. As to treatment he
says:

"The specific remedies for whooping cough (which have their season and
may be said now to include all drugs whatever of any potency) have all
of them a certain testimony in their favor. They agree in a single
point: whether by their nauseousness, the grievous method of their
application, or the disturbance they bring to the child's habits and
surroundings, the best vaunted remedies--emetics, sponging of the
larynx, ill-flavored inhalation, change of scene, beating with the
rod--all are calculated to _impress_ the patient, and find their use
accordingly.

BRITISH ASSOCIATION NOTES.

The committee appointed to test experimentally Ohm's law, that with any
conductor the electromotive force is proportioned to the current
produced, reports that this law is absolutely correct. If a conductor of
iron, platinum, or German silver of one square centimetre in section has
a resistance of one ohm for infinitely small currents, its resistance
when acted on by an electromotive force of one volt (provided its
temperature is kept the same) is not altered by so much as the millionth
of a millionth part. This fine result is the more gratifying since Ohm's
law is entirely empirical and does not rest at all upon logical
deduction.

The vast amount of water circulating through the solid earth is shown by
the calculations of the committee on the underground waters of the
Permian and New Red sandstones.

Taking an average rainfall of 30 inches per annum, and granting that
on