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least—even in healthy animals—the cardiac change should be present in a preponderating
degree, and should prove the determining factor in bringing about a dangerous collapse; in
other words, that death should sometimes be mainly due to cardiac failure, preceding the
cessation of respiration. Such I have actually found to be the case in at least three instances,
in a total of about seventy animals, where the decisive cause of collapse was the state of the
h e a r t . I s h a l l b r i e f l y s t a t e t h e m a i n f a c t o f t h e s e t h r e e c a s e s , i n w h i c h c h l o r o f o r m c o l l a p s e
was clearly due to cardiac failure, and where the natural respiratory efforts continued to be
manifested for prolonged periods after all signs of heart action had disappeared.
CASE I.—A cat was rendered unconscious by being put into a box with some chloro--
form. It was then taken out and more of the anæsthetic was administered in the ordinary
way—by chloroform on a cloth held near the animal's mouth and nose. The animal had not
been i n j u r e d i n a n y wa y , a n d h a d n o t b e e n f a s t e n e d d o wn , wh e n s u d d e n l y c o l l a p s e o c c u r r e d .
The heart been ceased to be felt and the pupils dilated widely, while natural respiration
went on regularly, though it soon became somewhat slowed and slightly spasmodic in character.
Air entered freely at each inspiratory movement. Artificial respiration—by rhythmically
compressing the chest
—was immediately begun, while pressure was applied to the abdomen.
The animal's spontaneous respiratory movements continued to go on regularly, while artificial
respiration was also carried on.
After this state of things had lasted for five minutes a canula
was put into the trachea (compression of the chest being meanwhile continued and the sponta-
neous respiratory movements still going on), then compression of the chest was discontinued,
and air was pumped into the chest from the bellows used for artificial respiration.
The spontaneous moti ons of breathi ng soon ceased, and a very few mi nutes l ater (tenm i n u t e s a f t e r
collapse had occurred) the thorax was opened and the heart viewed through the intact
pericardium. The whole organ was seen to be greatly distended, while rhythmical move-
ment of an exceedingly feeble and entirely ineffective character was still seen. The rate of
the futile contractions was quick. The ventricles were rhythmically compressed between the
thumb and forefinger at about the ordinary rate of the heart beat, and, after a period of
fibrillar contraction, the organ recovered its usual mode of action, the pulse was restored,
spontaneous respiratory efforts were again manifested whenever the artificial respiration was
intermitted, and tile whole condition of the animal continued, to be most satisfactory through-
out the course of a prolonged experiment
.
CASE II.—A cat, after being anæsthetised with chloroform in a box, was fastened on a
Czermak's support: a canula was tied in the trachea, and the left carotid artery was exposed.
When the animal was breathing spontaneously through the tracheal tube a little more
chloroform was given. The pulse quickly disappeared from the exposed carotid, and the
artery became small and collapsed. The respirations did not stop at all, but continued
without interruption; they soon assumed a slower and deeper type, and then went on steadily
i n
t h e s a m e f a s h i o n . P r e s s u r e o n t h e a b d o m e n , i m m e d i a t e l y a p p l i e d , h a d n oeffect
on
the
condi t i on of t he carot i d art ery: i t remai ned col l apsed as before. Art i fi ci al r e s p i r a t i o n , b y
rhythmical compression of the chest, was immediately begun and kept up for ten minutes,
during which time the spontaneous respiratory movements went on as before. Artificial
respiration, by blowing air into the lungs, was then commenced: the thorax w a s o p e n e d , a n d