3'o 



SCIENCE. 



[Vol. XVI. No. 409 



its retreat, left it hanging by a short line, while she pro- 

 ceeded, according to the usual habit of this kind of spider, 

 to carefully clean herself before the meal. Meanwhile I 

 managed to replace the fly by a piece of cork without dis- 

 turbing the spider. When the toilet was complete, she 

 pulled up the line from which the supposed fly was sus- 

 pended, and tried to eat the cork. She was a long time try- 

 ing ev^ery part of the cork before she finally let it drop. A 

 piece of an india-rubber ring was twisted up until it had ac- 

 quired a state {well known to school-boys) of spasmodic re- 

 coil. This was placed on the carpet-like web of a large black 

 house-spider, which Mr. Pocock tells me is known to natu- 

 ralists as Tegenaria atrica. These, like other house-spiders, 

 appear to be far more wary than the geometrical sort. The 

 india-rubber was made to move slightly by being pinched 

 from below, and then the spider pounced upon it. I did 

 not allow the spider to carry it off, but made it seem to 

 struggle and resist by manipulation with a pair, of forceps 

 under the web. The spider became more and more desper- 

 ate, and at last, when the web was much damaged by the 

 battle, I dragged the rubber away; but the spider could not 

 allow this, and clambering through the hole made in the 

 web, and hanging by her fourth pair of legs, seized the es- 

 caping insect. I then let go, and the spider carried the piece 

 of india-rubber away to her den, perfectly satisfied. How- 

 ever, she did not seem to appreciate her meal, for, after 

 biting it on every side, she was obliged to take it to the edge 

 of her web and drop it. I then picked it up, and was sur- 

 prised to find the spider willing to be similarly deceived 

 again. 



These spiders will come to a tuning-fork once or twice 

 perhaps, but the moment they touch it they fly terrified, as 

 they do from a common bluebottle with mica on its wings. 

 They seem generally thirsty, and will drink water placed 

 upon the web; and if it is scattered in drops, they are able 

 to find the drops, but by what process I do not know. The 

 diademas, too, especially when old, and only able to mend 

 old webs, not to spin new ones, are always ready to drink. 

 They will hold a piece of wheat straw six or eight inches 

 long which has a drop of water upon it until they have 

 drunk the water; but while the little spider is so insensitive 

 in taste as not to entirely reject a fly that has been soaking 

 in a parafBne lamp, especially if it is made to buzz with a 

 tuning-fork, the diadema has a strong objection to alcohol, 

 even well diluted, and rubs her mouth against any thing 

 near by after tasting it, so as to get rid as quickly as possible 

 of the noxious fluid. Is it possible that the numerous spi- 

 ders which are found in secondary batteries have been killed 

 by the acid when attempting to drink, or are they destroyed 

 by accidentally meeting the acid in their ordinary descents? 

 The Tegenaria is aware of the shout which causes the dia- 

 dema to strike and the little spider to drop, but the effect is 

 a jump such as is executed by any one when suddenly 

 startled. 



It would appear that the only sense which is developed to 

 any extent, and that most marvellously, is the sense of 

 touch ; hearing, taste, and smell to a small degree ; but sight, 

 as we understand the term, in spite of their numerous eyes^ 

 seems to be absent. The Tegenaria will stand within half 

 an inch of a fly feigning death, without being able to find 

 it; while the geometrical spiders, under like circumstances, 



gently pluck line by line until the effect of the inertia (not 

 weight) of a motionless object guides them to the proper 

 place. 



These remarks do not apply to the hunting spiders. 



C. V. Boys. 



THE PRODUCTION OF IMMUNITY FROM DISEASE. 



A RECENT despatch to the newspapers stated that Koch's 

 consumption "lymph '" had been analyzed by a Vienna doc- 

 tor, and that the principal ingredient was found to be a 

 substance which the chemists know as albumose. Professor 

 Koch himself, in his articles to the medical papers, does not 

 give the method of preparation of the " lymph,'" but indicates 

 that the material used is a sterilized culture liquid of the germ 

 that causes tuberculosis. 



This being the case, it is of interest to call attention to the 

 fact that the principle which Professor Koch is applying re- 

 ceived its first proof in a study of the fatal disease of hogs, 

 known as hog-cholera, made by Drs. Salmon and Smith of 

 the Bureau of Animal Industry, Department of Agriculture, 

 Washington, D.C., in 1887. To explain clearly what h.as 

 been done, it is a well-known fact that the germs which 

 cause different diseases in men and animals can be isolated, 

 and caused to multiply artificially outside of the body, by 

 supplying them with food. Some germs require one sort of 

 material, others a different one; but in general it may be 

 said that beef-broth, or blood serum, or glycerine and gela- 

 tine, are the most useful substances. These prepared solu- 

 tions are called culture liquids, or culture media. Into a tube 

 or flask of the liquid are introduced a few of the germs it is 

 desired to cultivate, and in a short time the germs are found 

 to have increased so enormously that they can be seen by the 

 naked eye. During this time great changes have taken 

 place in the culture solutions: what was at first harmless 

 beef-broth has been changed by the action of the germ to a 

 liquid, which, after the germs have been removed by filtra- 

 tion or killed by heat, still contains poisonous alkaloids and 

 albuminoids, which are generally fatal in their effects upon 

 the animal body. Alkaloids formed in this way are called 

 ptomaines; and the albuminoid bodies, albumoses; and each 

 distinct disease-germ forms a peculiar and distinct ptomaine 

 and albumose. The growth of the germ in the body is sup- 

 posed to form ptomaines and albumoses from the blood and 

 tissues, and these substances cause the fatal effects of the 

 different diseases. 



A horse can be gradually accustomed to arsenic; a man, to 

 opium, nicotine, strychnine, and quinia: so that after a time 

 a dose which would at first have been fatal to him can be 

 taken without injury. The idea suggests itself at once, why 

 not prepare and isolate the poisonous substances which germs 

 form, give them in small doses to men and animals, thus 

 gradually accustoming the body to their effect; and if then 

 the disease-germ afterwards enters the body, the system will 

 be already fortified against the poison which is produced, 

 and able to resist what would otherwise be its bad effects. 



This is exactly what Dr. E. A. v. Schweinitz, physiologi- 

 cal chemist in the Department of Agriculture at Washington, 

 D.C, has done in the case of the two diseases of hogs which 

 cause such enormous losses to the farmers of the country; 

 viz., hog -cholera and swine-plague. Dr. Schweinitz has made 



