May I, 1879] 



NATURE 



21 



transmitted from it to gun-cotton through very long lengths of 

 tube. In applying gun-cotton, on the other hand, to accom- 

 plish the detonation of mercuric fulminate, it was found that 

 this result could be attained, and through considerable lengths 

 of tube (7 feet and upwards) by means of very much smaller 

 quantities of gun-cotton than is needed of fulminate to induce 

 the detonation of gun-cotton through the corresponding distances. 



This want of reciprocity between two detonating agents 

 corresponds to one even more remarkable, which was observed 

 by the lecturer in his earlier investigations on this subject. In the 

 first place it was found that the detonation of \ oz. of gun- 

 cotton (the smallest quantity that can be thus applied) induced the 

 simultaneous detonation of nitro-glycerine, inclosed in a vessel 

 of sheet tin and placed at a distance of I inch from the gun- 

 cotton ; while with \ oz. of the latter, the same effect was pro- 

 duced with an intervening space of 3 inches between the two 

 substances. But on attempting to apply nitro-glycerine to the 

 detonation of gun-cotton, the quantity of the former, which was 

 detonated in close contact with compressed gun-cotton, was 

 gradually increased in the first instance to J oz. and subsequently 

 even to 2 oz. without accomplishing the detonation of the latter, 

 which was simply dispersed in a fine state of division, in all 

 instances but one in a large number of experiments. 



The force developed by the detonation of nitro-glycerine was 

 proved to be decidedly greater than that of the fulminate, of 

 which from 2 to J grains suffice for developing the detonation of 

 gun-cotton, when it is in close contact with them. The uon- 

 susceptibihty of gun-cotton to detonation by nitro-glycerine 

 is therefore, it need scarcely be said, not ascribable to any defi- 

 ciency in mechanical force suddenly applied when the uitro- 

 sjlycerine is detonated. 



( To be continued. ) 



INTELLECT IN BRUTES 



'pROM several additional letters which we have received on 

 this subject we select the following : — 

 Mr. Claypole, of Antioch College, Ohio, writes : — A friend 

 of mine is employed on a farm near Toronto, Ontario, where 

 a horse belonging to the wife of the farmer is never re- 

 quired to work, l)ut is allowed to live the life of a gentle- 

 man for the following reason : Some years ago the lady above- 

 mentioned fell off a plank bridge into a stream where the 

 water was deep. The horse, which was feeding in a field close 

 by, ran to the spot and held her up with his teeth till assistance 

 arrived, thus probably saving her life. Was jthis reason or in- 

 stinct? Again, a gentleman engaged in the business of distil- 

 ling at Cincinnati has more than once told me that the rats in 

 his distillery are in the habit of drinking any spirits spilt on 

 fhe ground or left in open vessels, and that they often become, 

 in consequence, so tipsy that they cannot run, and are easily 

 taken by hand. Which is this ? 



Mr. J. J. Furniss, of New York, writes: — Since the 



publication of my letter (Nature, vol. xix. p. 385) on 



the evidence of reasoning power in an elephant, afforded 



by the fact that he thatched his back with grass when 



exposed to the heat of the sun, I have received additional 



data bearing on the subject from Mr. W. A. Conklin, the 



superintendent of the Central Park Menagerie. I am informed 



by him that he has frequently observed elephants, when out of 



F doors in the hot sunshine, thatch their backs with hay or grass ; 



. that they do so to a certain extent when under cover in the 



summer time, and when the flies which then attack the animals, 



often so fiercely as to draw blood, are particularly numerous ; but 



that they never attempt to thatch their backs in the winter. This 



>ms to prove that they act intelligently, and for the attainment 



a definite end. It would be interesting to learn whether 



phants in their wild state are in the habit of so thatching their 



v-ks. It seems more probable to suppose that in their native 



.. lids they would avail themselves of the natural shade afforded 



liy the jungle, and that the habit is one which has been developed 



in consequence of their changed surroundings in captivity. I 



an^ also informed by Mr. Conklin that when taken to the 



water in summer the elephants first sprinkle their bodies all over 



with water, and then quench their thirst. They never so sprinkle 



I themselves in cold weather. Their reasoning in this case seems 



to be, " I cool my mouth by pouring water into it, now if I 



pour water over my back it will cool that also." Am I not 



justified in caUing this " abstract " reasoning? 



Mr. Charles Stewart, of Tighnduin by Killin, Perthshire, 

 sends the following story : — A few years ago I kept a collie dog 

 named " Bodach " at my farm, for herding the milk cows, and 

 who recognised the dairy-maid as his mistress. On her directing 

 him to keep the cows on a certain part of a field, he would lay 

 himself down in the centre of a line fixed by him as the proper limit. 

 Patiently and vigilantly he would remain in quietness until any of 

 the cows passed his limit, when he would swoop down on the 

 trespas-^er, take her by the heels, and drive her back. It was 

 wonderful in how short a time the cows came to recognise and 

 respect the arrangement. He also came to know some of the 

 cows by name. One of them named ' ' Aggi " required at certain 

 seasons to be milked oftener than the others, and the dairymaid 

 had only to say in GaeUc " Bodach, go and bring home Aggi," 

 when he would start for the pasture, single out Aggi, and bring 

 her carefully home. 



O. J. H. sends the following : — An ordinary domestic cat 

 was equally fond of a friend of mine and of myself. As 

 a test, we resolved to try the following experiment. We 

 each held a piece of bread, of the same size, shape, &c., 

 above the eyes of the animal. He looked at each hand 

 and its contents alternately, attempting to solve the problem of 

 getting at the bread without exhibiting partiality for either of 

 his frien is. He at last seemed to decide upon an expedient, for, 

 raising himself upon his hind legs, he simultaneously seized a 

 piece of bread in each of his front paws, and conveyed the food 

 thus obtained to his mouth. On repeating the experiment after 

 a lapse of some time, no difficulty was experienced in dealing 

 with the matter, as the expedient just mentioned was resorted to 

 without a moment's hesitation. 



Prof. Nipher, of Washington University, St. Louis, U.S., 

 writes : — A friend of mine living at Iowa City, had a mule, 

 whose ingenuity in getting into mischief was more than ordi- 

 narily remarkable. This animal had a great liking for the 

 company of an oat-bin, and lost no opportunity, when the yard 

 gate and barn-door were open, to secure a mouthful of oats. 

 Finally the mule was found in the barn in the morning, and for 

 a long time it was impossible to discover how he had come there. 

 This went on for some time, until the animal was " caught in the 

 act." It was found that he had learned how to open the gate, 

 reaching over the fence to lift the latch, and that he then effec- 

 tually mystified his masters, by turning round, and backing 

 against it, until it was latched. He then proceeded to the barn- 

 dour, and pulling out the pin which held the door, it swung 

 open of its own accord. From the intelligence which this animal 

 displayed on many occasions, I am of the opinion that had not 

 discovery of his trick prevented, it would soon have occurred to 

 him to retrace his steps before daylight, in order to avoid the 

 clubbing w hich the stable boys gave him in the morning. It 

 may be added that this animal had enjoyed no unusual educa- 

 tional advantages, and his owners found it to their interest to 

 discourage his intellectual efforts as much as possible. 



The Rev. George Henslow endeavours to sum up as follows 

 from the stories that have already appeared : — I am quite ready 

 to admit that more than one instance (notably Dr. Frost's cat, 

 which spread crumbs to catch birds, and which is paralleled by 

 one mentioned in Wood's "Natural History," which "chirped 

 like a sparrow, and so enticed and caught them), if correctly 

 stated, and if the motive of the animals could in every case be 

 proved, will completely overthrow my supposition that animals 

 never copy us with the same or a rational purpose. I cannot 

 help thinking, however, that such cases are very rare. More- 

 over, I will abandon my notion of abstract reasoning, at least, 

 as hitherto described, for I now think that what I meant by the 

 want of the faculty would be better described as an impotencfe, or, 

 at least, a feebleness of mind in concatenating correlative ideas ; 

 or, perhaps, a want of a receptivity of the suggestiveness of 

 things will express my meariing. On the other hand, I still see 

 no reason for believing that animals can conceive of a purely 

 abstract idea. Thus, "V. I." says a mule would turn on a tap, 

 but did not turn it off again. The reason I would suggest is that 

 ■wastefulness being an abstract conception, the mule could not 

 entertain it. If this be correct, we may now proceed a step 

 further. The idea of a personal Ego is purely abstract ; hence 

 I am led to believe that no animals can be self-conscious, and as 

 a direct consequence, they cannot be either moral or immoral, 

 but are simply automata and non-moral. Like children, they 

 can learn by being scolded, when they displease their master, so 

 that a conscience similar to a child's can be produced in them ; 



