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 �giat finds it harder to make comprcbensible to the laity, than that a frog, as a complete may be killed by destruction of its ner\'ous system, j^et moat of its oi^ans remaiD alive for hours ; also the fact that it is not ouly possible in mauy cases to isolate particular organs or cells, keepiug them alive for study after killing the rest of the plant or animal, but that this is even noueasarj', if the working of any complex organism is to be really understood. This popular ignorance, like all iguorance, has evil results. Much of the dis- quietude which many persons now feel in regard to physiological experiment is due to the fact that they do not realize that experi- ments on li\-ing hearts or muscles are usually carried out on animals which, as a whole, have previously been killed by destruction of the brain.

The KF.MARK&HLiii operation so successfully performed by Dr. William Fluhrcr of New York, involving no less a diffleulty than the probing of tlie brain -substance itself iu search of an embedded bullet, and the extraction of the missile through a counter- opening iu the skull opposite the |>oint of entrance, marks a new step in surgery which is slartliug in its suggestiveneas. It could hardly have been anticipated that so complete a recovery would follow an operation of such dilflculty and dan- ger, involving as it did the retention in the brain, for a prolongeil period of time, of a rub- ber drainage-tube passing completely through the head from the forehead to the back of the skull. The recovery is more remarkable on account of the .additional complication of a severed artery which could not be lied, mid which threatened speedy death from hemor- rhage. The case illustrates the value of an- tiseptic or aseptic ti'catment, ns well oa the possibility of removing much brain-tiesne in man, with thus far relatively little damage, which had already been demonstrated for other animals, notably for the dog. This had, how- ever, been fairly well established for man in some cases of injury, where the surgeon hail liffitated to interfere very actively. An ac-

��NCE. [Vol. v., So. 115.

count of this remarkable case will be found on another page. While its success would appear to justify- a similar procedure under like cir- cumstances, it is still far from certain that the next case would prove so easy of operation.

��LETTERS TO THE EDITOR. Mental capacity of an inlant.

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��Apropos of ' Acquisition iu intatila,' I ara t> to Btate the resulla of an experiment I made, n since, to test the mental cnpaclly of Helen R. H., on the day she was fifteen monlha old, walkin;; activelj, but speaking only half n doien words.

With pencil and paper, and several reliable wit- nesses present, I sat down, and without making but signs, or allowing sigua made by others, the mother and I t>egan to give the child a series of commaudi, the execution of which involved an accurate knowl- edge (if various verbs, nouns, and pronouns. Tiu commands were given distinctly, very seldom repeat- ed, and were obeyed very promptly, without any questioning or explanation whatever. In one lionr'i tune sixty-one commands were obeyed by the child with absolute precision, which showed a remem- brance and correct understanding of thirty-one verbi and fifty-one nouns and pronouns. The commandi given were such as the following: ' Kiss your hand,' 'Make a bow,' " Knock on the door,' ' Blow out thi candle,' ' Put the basket on the pail,' ' Put the pan in the pail,' ' Bring the bell, ball, orange,' etc The words used were such as the child had acquired a knowledge of by observation chiefly; tor not one- fourth of them had ever l>een taught her. I vitl add, that, while the child is possessed of wholesome brightness nnd Intelligence, she baa never been thought precocious. W. T. H.

Nutritive value of oelluloae.

In giving an account of some recent experiments upon the digestibility of cellulose by herbivoroui ani- mals (.Science, No, 100. p. 11), the writer took occv sion tn point out that the conclusions which certata writers had drawn from these experiments, r the nutritive value of digestible cellulose, ' sustained by the facts.

The last number of the Zriitehrifl pkr Molonie (sxi. 67) contains a paper by W. v. Knlerlem upon the utilization of cellulose in the animal organism, in which are detailed experiments upon the digesti- bility of cellulose, and upon its nutritive effect, which strikingly corroborate the belief above mentioned.

The method of experiment adopted is a novel one. It consisted In feeding the animals (usually rabbitaj with food containing no cellulose ; the necessary bulk Irelng supplied by noni -shavings, which were usu- ally eaten freely, and which, as special experiment* showed, were entirely unacted upon In the alimen- tary canal. After all the cellulose of the previous feeding bad thus t>een removed from the anlmaf, either a fodder containing a known amount of cellu- Iciie, or some more or less pure form of celluloM iiBKlf. was introduced into the ration. The solid exc^rementa wer« collected and analyzed in the usual way, and, by means of a return to I'he original c«Ila< lose-free ration, all the indigestible celluiose finally elimlaated from the bmly.

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