402 POPULAR SCIENCE REVIEW. 
Dilatation of Pupil simultaneous with general Muscular Exertion.— 
It would appear from the researches of M. It. VigouroUx that, whenever 
any energetic muscular movement, either of the body, or of inspiration or 
expiration, takes places, the pupil is dilated ; the dilatation varying from 
one-third to one-fifth of its previous diameter. This peculiar fact he thus 
explains : — Whenever a nervous centrifugal current traverses the spinal 
chord at the level of the origin of the first two pairs of dorsal nerves, 
a portion of the current is derived [diverted?] towards the pupillary 
filaments, which separate from their nervous centre, and effect the con- 
traction of the radiate fibres of the iris.— Ibid., and Gazette Medicale , 1863, 
p. 664. 
The Mechanical Power of Muscles. — A valuable paper on this subject 
was recently contributed to the Edinburgh New Philosophical Journal 
(vol. xviii.) by Mr. H. F. Baxter. His experiments- were carried out in 
the gastrocnemius muscle of a living frog, and his generalizations are thus 
expressed : — (1) One grain of muscle is capable of lifting a weight of 608 
grains through a space of T * T of an inch. (2) Sex has an important 
influence over the results ; males being, as a rule, more powerful than 
females. (3) The weight of the animal before the experiment gave no 
reliable indication as to the real muscular power. (4) During experiment 
there was a loss of weight of the animal, but an increase of weight in the 
muscle experimented on. (5) An increased nutrition of the muscle was 
indicated by its weight, its vascularity, increase in the activity of its elec- 
trical condition, and by the maintenance of its muscular power. (6) Cir- 
cumstances influencing the health of the animal, such as absence of food, 
temperature, and confinement, have an important influence over the 
results. (7) The maintenance of the circulation of the blood is of the 
utmost importance in these experiments. — Medico- Chirurgical Revievj , 
January, 1864. 
A New Remedy for Asthma has been described by Dr. McVeagh, in a 
late number of the Dublin Quarterly Journal of Medical Science. Whilst 
visiting an Irish nobleman who was attacked with asthma, lie learned 
from him that the seeds and plant of Datura tatula when smoked, invari- 
ably gave him relief, and that he first employed this remedy when at 
Malta. In the garden of the Governor of Malta large quantities of this 
thorn-apple are to be found, and the plant is used by the inhabitants as a 
cure for asthma. It has some advantages over D. stramonium , being more 
powerful as an antispasmodic and less so as a narcotic. It may be smoked 
like tobacco, or may be employed as tincture or extract ; the dose of the 
latter is from half a grain to a grain and a half, and of the former from 
20 to 60 minims. 
Are Vaccine Virus and Variolus Virus distinct? — We find that this 
question has recently been ably discussed in the French Academy of 
Medicine. M. Dupaul contended for the accuracy of the several conclu- 
sions, of which the following are a few : — (1) The vaccine, as a thing per 
se , has no existence'; it is nothing more nor less than the variolus virus. 
(2) That cows and sheep are, like man, subject to small-pox. (3) (The 
general and local phenomena seen in sUch cases in these animals are 
similar to those^observed irfman. (4) We may inoculate man from the 
