4 
March 22, 1883] 
NATURE 
485 
with water ; but fortunately the instruments all escaped 
unhurt, and nothing was lost but a pair of boots and a 
couple of hats, and all our salt and most of our sugar, 
which the water dissolved. 
For the next two days we were employed repairing the 
boat, it blowing a gale and raining hard the whole time, 
so that we could dry nothing; and when at last we 
started, almost constant head-winds and frequent gales 
made our journey a slow one. Fortunately our course 
lay among islands, so that we enjoyed a certain degree of 
shelter from the wind, and harbours of refuge were 
always at hand in case of necessity. These islands 
are all of rock and well wooded, but destitute at this 
season of the year of game, which was unfortunate for 
us, aS Our provisions were getting short, and our crew 
were reduced to a pound of flour per diem, with a little 
tea and sugar. There were not even fish to be caught, 
though they are usually abundant, but I suppose the 
rough weather had driven them into the deep water. At 
last we shot some seagulls, and we were all glad enough 
to eat them. 
At length, on the 30th, we reached Fort Rie, which 
lies in lat. 62° 38’ N. and long. 115° 25’ W., half way up a 
long gulf that runs for about 109 miles in a north-west 
direction from the mouth of the Yellow Knife River. 
The fort is situated at the foot of a rocky hill that rises 
some 200 feet above the lake, which is about four miles 
wide at this point. The Indians who resort here for trade 
hunt for the most part in the “barren lands” near the 
Coppermine River, whence they bring quantities of skins 
‘and beef from the musk-ox, which seems to be very 
abundant. Deer too are very plentiful, and in the winter 
‘they migrate in great herds from the barren lands to the 
country between the arm of the lake on which Fort Rae 
lies and the Mackenzie. Sometimes these herds pass 
quite close to the fort, and take two or three days in 
passing. Their numbers must be very great; a single 
band has been known to kill over 15,000 in an ordinary 
season. 
This year the deer have passed at some distance, but 
ithe Indians are now bringing in fresh meat daily. 
These Indians are of the “ Dog-rib’’ tribe —T’ akfwel- 
jotting, they call themselves—a quiet, inoffensive race, 
like all the wood-Indians. They are almost all Roman 
Catholics, the missionaries of that religion being very | 
numerous in the country, and they are certainly very 
{devoted and hard-working. There are also Protestant 
missionaries, but they do not appear to have made any 
converts. 
| The Dog-ribs are a branch of the Chipewyan family 
ywhich occupies all that portion of the continent between | 
ithe Rocky Mountains and Hudson’s Bay to the north 
‘of the parallel of 55°. They are unprepossessing in 
appearance, and their language is almost unpronounce- 
ble by a European. Their alphabet, if they had one, 
ould contain no less than seventy-one letters, that being 
‘the number of distinct sounds. I believe the language is 
llied to the ancient Mexican—at any rate the Navajo is 
he nearest to it of existing languages—and the combina- 
ions of letters that one sees in Mexican names (dd, for 
nstance) are common in this language. The Dog-ribs 
ave the remarkable peculiarity of a national habit of 
tammering, which is most marked in those who seldom 
ome in to the fort. They treat their women with more 
indness than is usual among the American Indians. 
Fort Rae is one of the windiest and cloudiest places I 
ave ever seen, but I am told this is an exceptional year. 
t is certainly a very late autumn ; the lake was not frozen 
ill November 1, and it is only within the last day or two 
hat the cold weather has really set in. Last night the 
thermometer was at — 34°. 
My space is at an end, but by the next mail I hope to 
j you an account of our winter here. 
} 
| 
Fort Rae, December 1 
ON THE NATURE OF INHIBITION, AND THE 
ACTION OF DRUGS UPON IT* 
IV. 
CONDITION very nearly similar to that caused by 
atropia is produced by morphia. When this sub- 
stance is given to a frog, its effects are exactly similar to 
those produced by the successive removal of the different 
parts of the nervous system from above downwards. Goltz 
has shown that when the cerebral lobes are removed from 
the frog it loses the power of voluntary motion and sits 
still; when the optic lobes are removed it will spring when 
stimulated, but loses the power of directing its move- 
ments. When the cerebellum is removed it loses the 
power of springing at all; and when the spinal cord is 
destroyed reflex action is abolished. 
Now these are exactly the effects produced by morphia, 
the frog poisoned by it first losing voluntary motion, next 
the power of directing its movements, next the power of 
springing at all, and lastly reflex action. But after reflex 
action is destroyed by morphia and the frog is apparently 
dead, a very remarkable condition appears, the general 
flaccidity passes away and is succeeded by a stage of 
excitement, a slight touch causing violent convulsions 
Just as if the animal had been poisoned by strychnia.2 
The action of morphia here appears to be clearly that - 
of destroying the function of the nerve centres from above 
downwards, causing paralysis first of the cerebral lobes, 
next of the optic lobes, next of the cerebellum, and next 
of the cord. But it seems probable that the paralysis of 
the cord first observed is only apparent and not real, and 
in order to explain it on the ordinary hypothesis we must 
assume that during it the inhibitory centres in the cord 
are intensely excitel so as to prevent any motor action, 
that afterwards they become completely paralysed, and 
thus we get convulsions occurring from slight stimuli. 
On the hypothesis of interference, the phenomena pro- 
| duced both by atropia and by morphia can be more simply 
explained. These drugs, acting on the nervous structures, 
gradually lessen the functional activity both of cells and 
of fibres ; the impulses are retarded, and thus the length 
of nervous connection between the cells of the spinal cord, 
which is calculated to keep them in proper relation in 
the normal animal, just suffices at a certain stage to throw 
the impulses half a wave-length behind the other, and 
thus to cause complete inhibition and apparent paralysis. 
As the action of the drug goes on, the retardation be- 
comes still greater, and then the impulses are thrown very 
nearly, but not quite, a whole wave-length behind the 
other, and thus they coincide fora short time, but gra- 
dually again interfere, and therefore we get on the appli- 
cation of a stimulus, a tonic convulsion followed by 
several clonic ones, and then bya period of rest. This 
explanation is further borne out by the fact observed by 
Fraser, that the convulsions caused by atropia occurred 
more readily during winter, when the temperature of the 
laboratory is low and the cold would tend to aid the 
action of the drug in retarding the transmission of 
impulses.® ; 
The effect of strychnia in causing tetanus is very re- 
markable; a very small dose of it administered to a frog 
first renders the animal most sensitive to reflex impulses, 
so that slight impressions which would normally have no 
effect, produce reflex action. As the poisoning proceeds, 
a slight stimulus no longer produces a reflex action limited 
to a few muscles, but causes a general convulsion through- 
out all the body, all muscles being apparently put equally 
on the stretch. In man the form assumed by the body is 
that of a bow, the head and the heels being bent back- 
wards, the hands clenched, and the arms tightly drawn 
to the body. 
* Continued trom p. 468. 
® Marshall Hall, Memoirs on the Nervous System, p. vii. (London, 
1837). Witkowski, Archiv fiir exper Path. und Pharm., Band vii. p. 247+ 
Transactions of the Royal Society of Edinburgh, vol. xxv. p. 467. 
