September 1, 1897.] 



KNOWLEDGE. 



205 



of this, but it was on the glass outside the green- 1 

 house, whilst I was inside and the door was locked. 

 My feelings at that moment can be better imagined than 

 described. 



Camphmctus cinctns (Fig. 1, male — Figs. 2 and 3, female) 

 has received a good deal of attention and notoriety from 

 the fact that in 1862 Sir John Lubbock discovered 

 that it was aquatic in its habits, using its wings for 

 swimming under water (Fig. 2). It was christened 

 Pohjncma natans by the worthy discoverer of its natatorial 

 habits ; but in 1896 it fell to my lot to prove it to be iden- 

 tical with Haliday's Cdraphyactus. Further research has 

 proved that the mymarid bred by M. Ganin from eggs of 

 the dragon fly is not (as has been stated) identical with 

 Caruphraclus. At the same time that Sir .John Lubbock 

 observed this aquatic fairy he also discovered another 

 aquatic Hymemipteron, which used its legs only for swim- 

 ming ; this he named Pivxtwichia aquatica — and though 

 Kev. T. A. Marshall has included it in his list of British 

 Mymarida, it has no right to such a place. Fig. 6, the 

 female, shows a very distinct subcostal nerve turning 

 inwards and ending abruptly, which feature is never found 

 in any of the Mijmaridce. It was not until June 20th, 

 1896, that I had the pleasure of first discovering the male 

 (Fig. 7) of this interesting Hymenopteron. It has the 

 merest rudiments of wings. 



Anaphes is found in almost any garden, and is frequently 

 confounded with Eustochus, but the solid club is an 

 unfailing character. It is also somewhat larger than 

 Eustochus. 



Anagrus contains many species of very delicate yellow 

 fairy flies, always present in gardens and about ponds — in 

 fact, almost everywhere. I have been again fortunate in 

 discovering the life history of several species belonging to 

 this genus. One is parasitic m eggs of dragon flies, and 

 three others in different kinds of eggs of frog-hoppers, 

 which have for over thirty years eluded my search until 

 the present year. 



One more genus remains to be noticed, and it is the 

 most fairylike of all the Mymarida, viz., CamptopUra 

 papavcris. It is the smallest of the family, the female 

 being but one eighty-fifth of an inch long. Mystery sur- 

 rounds this gem, and yet it is most plentiful in certain 

 localities — Woking for instance, where, on one day, Sep- 

 tember Gth, 1885, I caught over three hundred females 

 crawling up the windows facing east. The male, of which 

 I have only taken two specimens, measures just one ninety- 

 second of an inch from head to tail, and yet is absolutely 

 perfect in every part. 



MORE ABOUT ANTIVENENE. 



By Dr. J. G. MoPherson, F.R.S.E., 



Mathematical Examiner in thr Vniversity of 



St. Andivw's. 



TWO years ago we gave the digest of two lectures by 

 Prof. Fraser, of Edinburgh, on the cure for snake 

 bites. Having ascertained the minimum dose of 

 snake poison 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 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. 

 The blood serum of these immunized animals, which he 

 named " antivenene," was then used as an antidote for the 

 venom. He took a fresh animal and injected the poison, 



as in a snake bite, waiting till symptoms of poisoning were 

 manifest ; at once he injected the antiventne, and put a 

 stop to any further progress of the poisoning. This showed 

 that the antivenene is really an antidote to the poison of 

 snakes. 



In the course of his experiments. Prof. Fraser observed 

 a peculiar fact, viz., that dietary had an efl'ect upon venom 

 poisoning. Venom is almost inert when introduced into 

 the stomach, or any other part of the alimentary canal. 

 By gradual increases, he introduced at one time into the 

 stomach of a cat a dose of venom eighty times larger than 

 would have killed a clean cat by injection, yet no observable 

 disturbance was produced by these doses. 



Carrying on his experiments. Prof. Fraser examined the 

 antivenomous properties of the bile of serpents and other 

 animals, and he has just given to the Royal Society of 

 Edinburgh an explanation of the unsusceptibility of 

 animals to the poisonous action of venom introduced into 

 the stomach. After repeated experiments on white rats, 

 he found that when the snake's poison is introduced into 

 the stomach it does not produce any active poisoning 

 effects, but some of it seems to become absorbed into the 

 animal's blood so as to assist in the immunization. Why 

 was this ■? In Prof. Eraser's opinion, when venom is 

 introdixced into the stomach, the chemical changes wrought 

 by the acids of the stomach destroy its fatality to a 

 large extent. With the view of proving this he made 

 experiments upon rabbits with a mixture consisting of 

 a lethal dose of venom and varying quantities of the 

 bile of the African cobra, the rattlesnake, and the pufl"- 

 adder — three of the most deadly of the serpent tribe. 

 This mixture was not introduced into the stomach, but 

 injected subcutaneously. When the proportion of bile was 

 small, the animal operated upon invariably died within 

 three or four hours ; but when the quantity of bile was 

 increased the animal recovered after a period of torpor. 

 He also experimented with a mixture consisting of a 

 lethal dose of African cobra venom and the bile of the 

 grass snake — an innocuous serpent ; but in this case he 

 found it was necessary to increase very largely the dose of 

 the grass snake bile — nearly seventy times greater — before 

 results not terminating in death were obtained. He is 

 now of opinion that the bile of all animals is more or less 

 antivenomous, but the more venomous of the serpents 

 produce the most effective bile. It would not do, he con- 

 sidered, to inject subcutaneously a quantity of bile taken 

 from a venomous serpent into a person, say, half an hour 

 after being bitten by a venomous serpent, sufficient to 

 render the venom harmless, because the bile would most 

 probably itself produce death by its own poisonous proper- 

 ties. It must be introduced through the stomach or applied 

 to the wound. 



He had experienced great difficulty in getting a supply 

 of serpent bile in its natural state, so he got a friend of his 

 in India to send him a small quantity of alcoholic pre- 

 cipitate of cobra bile, with which he experimented ; but 

 the results were not quite so satisfactory. As a further 

 proof that bile is able to render venom innocuous, he stated 

 that it wy,s now a well-known fact that it enters into the 

 composition of all the wonderful remedies used by Indian 

 snake doctors for snake bites ; although they do not care to 

 admit the correctness of it, as they fear to say anything 

 which would lessen their hold upon the superstitious feelings 

 of the people. Serpent bile is so difficult to obtain that 

 the snake doctors usually employ venom as an antidote in 

 the first place ; and only when this shows certain signs of 

 failure do they fall back on their precious store ol bite. 

 They rub it into the wound. 

 Bile is secreted in large quantities by all animals, and 



