580 
OLOF SCHWARZKOPF. 
lungs, etc. This theory has been forgotten by the present gen¬ 
eration of veterinarians, but if signs are true it may be revived 
m a modified form. Besides the later theories of English writ¬ 
ers which are known to you, there is that of Harms, of Hanover, 
who explained it as a result of suction of air into the blood ves¬ 
sels during parturition, followed by cerebral anaemia and paresis. 
This hypothesis was born at a time when fatal results were ob¬ 
tained by the absorption of air during operations in the early 
days of modern surgery, and it was apparently substantiated 
by the presence of air globules in cerebral vessels, a condition 
which later researches have shown to be the result of post-mor¬ 
tem blood decomposition. Then, there is the theory of Frank, 
of Munich, who considered the disease a result of the sudden 
and grave circulatory changes as produced by the abrupt loss of 
a large^ area of blood circulation in the uterus, forcing large 
quantities of blood into new channels, especially the brain, thus 
producing cerebral congestion, followed by encephalic oedema 
and anaemia. This complex theory, based on an intimate anatom¬ 
ical Study of foetal and uterinal circulation, withstood the scien¬ 
tific criticism of years and was until recently accepted all over 
the Continent of Europe. But of late it has been more or less 
superseded by the more modern theory of Schmidt-Muhlheim, 
who advanced the theory that tjie disease was due to auto-intoxi- 
cation by certain cadaveric alkaloids similar to the sausage-poi¬ 
son. He argued that these poisons develop within the uterus 
by the decomposition of the lochia, favored by the rapid occlu¬ 
sion of the neck of the uterus as observed in milk fever. He 
based his theory on the result of the researches in experimental 
poisonings of Hoppe-Seiler, who discovered that a number of 
alkaloids, especially ptomatropine, ptomacurarine, and mytilo- 
toxine, produce a paralysis of certain muscular groups, such as 
the pharynx, eye, etc., and in severe cases end in a paresis of 
the striated muscular-fibres of the extremities and the unstriated 
fibres of the intestine and blood-vessels. No one can deny that 
these symptoms have a striking resemblance to those so 
commonly exhibited by milk fever. This brief review of the 
