164 



KNOWLEDGE 



[July 1, 1«95. 



sense of the term." A striking illustration of Dr. Gray's 

 meaning may be seen in Kew Gardens any day, for there 

 is flourishing there a branch ofJ'shoot of the great dragon 

 tree of Orotava, Teneriti'e, which was blown down in a 

 terrific gale in 1868. That particular specimen of the 

 genus Liliacecs ■WHS of vast size and great age, an object of 

 worship by the natives when discovered, fully live hundred 

 years ago. When Humboldt visited the island in 1799, 

 he found the tree seventy-five feet in height, fifty feet in 

 girth, " with an internal cavity about ten feet in diameter." 

 At the time of its destruction the tree was probably over 

 two thousand years old, and must have weathered 

 hundreds of terrific thunder-storms. 



THE CURE FOR SNAKE-BITES. 



By Dr. -T. G. McPheeson, F.E.S.E. 



PROFESSOR ERASER, of the University, has just 

 laid before the Royal Society of Edinburgh the 

 result of his e.xperiments on snake-bites. For a 

 quarter of a century Dr. Eraser has been one of 

 the foremost authorities on toxicology, and this 

 last discovery will be an inestimable boon to the dwellers 

 in India, who are exposed to the poison of snakes. 



The poison-gland of venomous snal;es lies on each side 

 behind the eye, and is about the size of an almond in the 

 cobra. From this gland a duct extends to the base of 

 the fang, down which the venomous juice flows when the 

 snake bites its victim. By a muscular arrangement the 

 poison-gland is automatically compressed when the snake 

 opens its mouth to strike. But the opening of the mouth 

 also brings about the erection of the fangs, which are 

 recumbent when not used. The juice formed in the 

 specialized glands and forced out along the fangs is a clear, 

 viscid fluid, which may be kept for months or even years 

 without losing its virulence. Injected through the fangs 

 into the blood of a victim, it tends to paralyze the nerve- 

 centres, and may prove fatal. 



The extent of the mortality from snake-bite among 

 inhabitants of warm countries is little known by Euro- 

 peans ; but in British India alone the deaths of persons 

 reported from this cause varied from 18,070 in 1881 to 

 22,480 in 1889. During that decade rewards were paid 

 for snakes destroyed to the number of 212,776 in 1880 to 

 578,415 in 1889 ; but this result is less satisfactory when 

 it is known that in some places snakes are actually bred in 

 order to secure the payment for their heads. 



Many in India have been deceived with the idea that 

 they have antidotes for snake-poison. In this country 

 nearly every drug has been recommended — ammonia, 

 permanganate of potash, arsenic, iodine, bromine, the 

 poison of other snakes, the guaco plant, ipecacuanha, 

 senega, aristolochia. But the distinguished authority on 

 snake-poisons, Sir Joseph Fayrer, has no faith in any of 

 these. Until Prof. Fraser's experiments have proved that 

 he has hit upon the means of curing the victim, no reliable 

 antidote was forthcoming. 



The coloured charts and tables exhibited by Pi-of. Eraser 

 showed the enormous amount of work which he has done 

 in connection with the subject. He had great ditticulty in 

 getting a sutHcient supply of venom to allow him to com- 

 mence his experiments. He has been collecting for the 

 last five years, and he has been getting it from India, 

 Africa, America and Australia ; but it was only at the end 

 of last year that he had received enough to start with. 

 The best of his supply has been sent from India. He 

 showed some specimens dried and powdered and carefully 



sealed up in little bottles. It was peculiar-looking stuff, 

 something like brown sugar, but not so sticky. His experi- 

 ments, when completed, should give results which will be 

 of great practical importance. He has proved that there is 

 great ti'hirttion for snake-poison. This is his first success- 

 ful discovery. Having ascertained the minimum dose 

 required to cause the death of an animal, he started below 

 that amount and gradually increased the dose after intervals 

 of ten days. By this process of gradual increases in the 

 dose of the snake-poison, he found the animal receiving as 

 much at one time as fifty times the amount of the minimum 

 lethal dose without it causing any bad effects to the animal. 

 In fact its general health seemed to improve, as he had 

 the animals weighed once and sometimes twice every day ; 

 and all the tiuie he was administering the venom there 

 was a steady increase in weight. 



In the meantime, Prof. Eraser has not carried his 

 experiments of quantity further than fifty times the 

 minimum lethal dose at one time ; but still, when he had 

 got to that point, the animal was receiving in a single 

 dose, without being affected, enough to kill fifty animals of 

 the same size and weight. One of the animals which he 

 had treated by this gradually increasing quantity, had, in 

 two months, received enough poison to kill three hundred 

 and seventy fresh animals of equal size and weight, 

 supposing that each just got the minimum lethal dose. 

 This is a very successful instance of toleration. 



He then described a second series of experiments, in 

 which he used the blood-serum of these animals, which had 

 been immunized, as an antidote for the venom. He mixed 

 an equal part of this blood-serum and venom together, and 

 injected the mixture into a fresh animal. This produced 

 no efi'ect, the serum counteracting the action of the poison. 

 Next, he injected some of the immunized blood-serum, 

 which he has named antircnine, into a fresh animal ; and 

 then some veuom afterwards ; but the serum hindered any 

 action of the venom. Then he took another fresh animal, 

 and injected the venom, waiting till symptoms of poisoning 

 were manifest ; at once he injected his antivenine, and 

 piit a stop to any further progress of the poisoning. The 

 same results took place after many experiments. All this 

 points to the conclusion that this antivenine, or blood- 

 serum, in an animal that has been able to stand with 

 impunity fifty lethal doses at a time by the increasing dose 

 process, is really an antidote to the poison of snakes. 



Prof. Eraser is at present immunizing a horse, but he 

 has not enough veuom to finish the work. He has only 

 got nine grammes, and still requires thirty ; but the 

 Indian Government is trying hard to secure it for him. 

 This he expects to receive before long. When the horse 

 has been immunized, he expects to get enough antivenine 

 from its blood-serum to allow of its being tested chemi- 

 cally, so as to ascertain the substances which antagonize 

 the venom. In this way it is hoped, the ingredients being 

 known, the antivenine can be chemically prepared. 



This discovery will be of great practical importance, for 

 the antivenine can be prepared and sent out to India in 

 small bottles for immediate use in the case of snake-bites. 

 But, even as it is, the discovery of antivenine itself is a 

 most valuable one, and gives evidence of the great advance 

 made in medicine during recent years, when the thyroid 

 preparation for myxanlema and the antitoxin for diphtheria, 

 and such like, have startled the medical world. The 

 attempt made by the Indian Government to clear out 

 snakes, by payment of so much for a snake's head, will 

 evidently be less successful than the extirpation of wolves 

 in Wales by a similar method ; for the fact is, that the 

 number of snakes is really increasing. It is to the anti- 

 venine which Prof. Eraser will be able to prepare by 



