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POPULAR SCIENCE REVIEW. 
febrile affections to these obliterations of vessels in the grey matter of the 
brain ; and he is also disposed to think that the albuminuria so frequently 
met with in these affections may be explained by a similar affection in the 
kidney. These observations, says the British Medical Journal, open up an 
extensive field of further pathological research and clinical deduction. 
The Contractions of the Heart . — In a lecture delivered at the Royal In- 
stitution on February 11, which formed part of his course on the Involun- 
tary Movements of Animals,” Dr. Michael Foster exhibited the heart of a 
recently killed tortoise, which heart was placed in a platinum dish, where it 
continued to expand and contract with great steadiness. A long lever arm 
of straw had its shorter end fixed in contact with the heart, so that the 
other end of the lever moved up and down two inches with each motion of 
the organism, thus making the motions visible to the whole audience. The 
motion of the heart of another recently killed tortoise was made visible in 
the same way, though in the latter case the heart was not removed from 
the body. The lecturer said that he could not exhibit the heart of a warm- 
blooded animal in this way, because in such animals it ceases to beat within 
a few minutes instead of hours after the death of the brain, in consequence 
of the rapid way in which such hearts consume their nutrition. Cold- 
blooded animals like frogs have plenty of capital in the shape of nutrition 
inside their bodies, and can go without food for a long time. When the 
heart of a frog is cut into two or more pieces each part continues to beat, 
except the lowest point of the heart, which exhibits no motion when it is 
cut off. The nerves entering the great muscle, called the heart, have cells 
attached to them after their entrance, and to these nerve cells, which are 
found in all parts of the heart except the lower point, the observed motions 
seem to be in some way due. 
Skin Tissue affected in Small-pox . — Herr Erismann has explored this 
pathological region, and has laid his results before the Academy of Vienna. 
He believes that the first trace of the disease is seen in the upper layer of 
the derma, and in the Malpighian layer of the epidermis ; the blood-vessels 
of the papillae of the derma exude liquid matter, which forms cells that 
penetrate into the Malpighian layer, and form the true small-pox pustule. 
The capillary follicle is only secondarily affected, and the capillary papilla 
hardly ever is involved in the destruction of parts. In haemorrhagic variola 
the affection commences in the corium around the capillary follicle, and 
penetrates into the papilla, whose vessels are crowded with exudative corpu- 
scles. He has found no traces of cryptogamic vegetation in any of the 
morbid specimens, which he placed in chromic acid for examination. 
Influence of Pneumogastric Nerves mi liesjyiration . — A paper by Herr Voit 
and Rauber appears in the report of the Academy of Sciences of Munich. 
It has been concluded from previous experiments of other physiologists that 
the amount of carbonic acid exhaled after section of the nerve is the same as 
that before. Herr Voit and Dr. Rauber find now that this is true only for the 
first few hours after the operation. At a later period, when the issue of the 
lung has begun to undergo a change, tlie quantity of carbonic acid dimin- 
ishes rapidly, and tliat of oxygen is increased. 
Sulphurous Acid in the Atmosphere. — Mr. Peter Spencer, in a paper on 
the presence of this acid in the air of Manchester, makes the following 
