306 



SCIENCE 



[Vol. V., No. 115. 



gist finds it harder to make comprehensible 

 to the laity, than that a frog, as a complete 

 animal, may be killed by destruction of its 

 nervous system, yet most of its organs remain 

 alive for hours ; also the fact that it is not only 

 possible in many cases to isolate particular 

 organs or cells, keeping them alive for study 

 after killing the rest of the plant or animal, 

 but that this is even necessary, if the working 

 of any complex organism is to be really 

 understood. This popular ignorance, like all 

 ignorance, 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 living hearts or muscles are usually 

 carried out on animals which, as a whole, 

 have previously been killed by destruction of 

 the brain. 



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. 



The remarkable operation so successfully 

 performed by Dr. William Fluhrer of New 

 York, involving no less a difficulty than the 

 probing of the brain-substance itself in search 

 of an embedded bullet, and the extraction of 

 the missile through a counter-opening in the 

 skull opposite the point of entrance, marks a 

 new step in surgery which is startling in its 

 suggestiveness. It could hardly have been 

 . anticipated that so complete a recovery would 

 follow an operation of such difficult}' and dan- 

 ger, involving as it did the retention in the 

 brain, for a prolonged 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 tied, and 

 which threatened speedj T death from hemor- 

 rhage. The case illustrates the value of an- 

 tiseptic or aseptic treatment, as well as the 

 possibility of removing much brain-tissue 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 had 

 hesitated to interfere very actively. An ac- 



LETTERS TO THE EDITOR. 



Mental capacity of an infant. 



Apropos of 'Acquisition in infants,' I am tempted 

 to state the results of an experiment I made, not long 

 since, to test the mental capacity of Helen R. H., on 

 the day she was fifteen months old, walking actively, 

 but speaking only half a dozen words. 



With pencil and paper, and several reliable wit- 

 nesses present, I sat down, and without making any 

 signs, or allowing signs made by others, the mother 

 and I began to give the child a series of commands, 

 the execution of which involved an accurate knowl- 

 edge of various verbs, noans, and pronouns. The 

 commands were given distinctly, very seldom repeat- 

 ed, and were obeyed very promptly, without any 

 questioning or explanation whatever. In one hour's 

 time sixty-one commands were obeyed by the child 

 with absolute precision, which showed a remem- 

 brance and correct understanding of thirty-one verbs 

 and fifty-one nouns and pronouns. The commands 

 given were such as the following: ' Kiss your hand,' 

 ' Make a bow,' ' Knock on the door,' ' Blow out the 

 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; for not one- 

 fourth of them had ever been taught her. I will 

 add, that, while the child is possessed of wholesome 

 brightness and intelligence, she has never been 

 thought precocious. W. T. H. 



Nutritive value of cellulose. 



In giving an account of some recent experiments 

 upon the digestibility of cellulose by herbivorous ani- 

 mals {Science, No. 100, p. 11), the writer took occa- 

 sion to point out that the conclusions which certain 

 writers had drawn from these experiments, regarding 

 the nutritive value of digestible cellulose, were not 

 sustained by the facts. 



The last number of the Zeitschrift fur biologie 

 (xxi. 67) contains a paper by W. v. Knieriem 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 rabbits) 

 with food containing no cellulose; the necessary bulk 

 being supplied by horn-shavings, which were usu- 

 ally eaten freely, and which, as special experiments 

 showed, were entirely unacted upon in the alimen- 

 tary canal. After all the cellulose of the previous 

 feeding had thus been removed from the animal, 

 either a fodder containing a known amount of cellu- 

 lose, or some more or less pure form of cellulose 

 itself, was introduced into the ration. The solid 

 excrements were collected and analyzed in the usual 

 way, and, by means of a return to the original cellu- 

 lose-free ration, all the indigestible cellulose was 

 finally eliminated from the body. 



