302 POISONS : THEIR EFFECTS AND DETECTION. [§ 363 . 
cooled violet-coloured solution either a crystal of nitrate of potash or of 
chlorate of potash, or a drop of dilute nitric acid, a beautiful violet-blue 
colour is produced, which passes gradually into a dark blood-red. 
yJo of a mgrm. will respond distinctly to this test. Frohde’s reagent 
strikes with morphine a beautiful violet colour, passing from blue into 
dirty green, and finally almost vanishing, of a mgrm. will respond 
to the test, but it is not itself conclusive, since papaverine and certain 
glucosides give an identical reaction. 
§ 363. Symptoms of Opium and Morphine Poisoning. —The symptoms 
of opium and morphine poisoning are so much alike, that clinically it 
is impossible to distinguish them ; therefore they may be considered 
together. 
Action on Animals—Frogs. —The action of morphine or opium on 
frogs is peculiar ; the animal at first springs restlessly about, and then 
falls into a condition extremely analogous to that seen in strychnine 
poisoning, every motion or external irritation producing a tetanic con¬ 
vulsion. This condition is, however, sometimes not observed. The 
tetanic stage is followed by paralysis of reflex movements and cessation 
of breathing, the heart continuing to beat. 
Dogs. —0-2 to 0-5 grm. of morphine meconate, or acetate, injected 
directly into the circulation of a dog, shows its effects almost immediately. 
The dog becomes uneasy, and moves its jaws and tongue as if some 
peculiar taste were experienced ; it may bark or utter a whine, and then 
in a minute or two falls into a profound sleep, which is often so deep 
that while it lasts—usually several hours—an operation may be per¬ 
formed. In whatever attitude the limbs are placed, they remain. The 
respiration is rapid and stertorous, and most reflex actions are extin¬ 
guished. Towards the end of the sleep, any sudden noise may startle 
the animal, and when he wakes his faculties are evidently confused. 
A partial paralysis of the hind leg has often been noticed, and then the 
dog, with his tail and pelvis low, has something of the attitude of the 
hyena. Hence this condition (first noticed by Bernard) has been 
called the “ hyenoid ” state. If the dose is larger than 2 to 3 grms. 
(31 to 46 grains), the symptoms are not dissimilar, save that they 
terminate in death, which is generally preceded by convulsions. 1 
1 MM. Grasset and Amblard have studied the action of morphine in causing con¬ 
vulsions in the mammalia. They found that if small doses of hydrochloride of 
morphine (from 1 to 15 centigrammes) are administered to dogs, the brief sleep which 
is imoduced may be accompanied by partial muscular contractions (in one paw, 
for instance), which are renewed at variable intervals. Then occur true convul¬ 
sive shocks in the whole body or in the hind limbs. After an interval, the pheno¬ 
mena recur in more intense degree, and are followed by true convulsions. Regularly, 
ten 01 sixteen times a minute, at each inspiration, the hind limbs present a series of 
convulsive movements, which may become general. Sometimes they are excited 
by external stimulation, but they are usually spontaneous. The sleep may continue 
profound during this convulsive period, or it may become distinctly lighter. These 
