NA TURE 



[December 5, 1901 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsihie for opinions ex- 

 pressed hy his correspondents. Neither can he undcrtahe 

 to return^ or to correspond with the ivriters of rejeciei 

 inantiscrtpts intended for this or any other part of NatUKE. 

 No notice is taJcen of anonvmoiis coinmtinications.'i 

 Automatic Actions. 



In the interesting paper on "Reflex Action" by Dr. W. 

 Benthall, published in your issue of September 5, he spealis of 

 acquiring some feat of manual dexterity in which, with practice, 

 the required muscular action becomes automatic. It seems to 

 me that the same rule applies to many operations which are 

 generally regarded as purely mental, such as in the use of the 

 first four rules in arithmetic, in writing grammatically and 

 spelling correctly, and in speaking any language. If you think, 

 the action becomes laborious and in all cas* the result is un- 

 certain. In the case of spelling this seems to occur to every 

 one, so that if you have to look up one word in a dictionary, 

 which shows that you have begun to think about spelling, you 

 have immediately to look up a number of others. Many people 

 who are employed as clerks, &c. , no doubt in adding a column 

 of figures have their minds completely blank without their 

 knowing it. In my own case, both at school and afterwards, 

 I was very slow at this process and very uncertain of the re- 

 sults if the figures were numerous, as in a money column, but 

 I found out, more than twenty years after I left school, that by 

 thinking, not of the figures, but of nothing, the process was easy 

 and rapid and the results correct. In speaking, say, French, 

 if a person has to think of grammatical rules, the gender of 

 nouns, i&c, he can never speak fluently ; to do so he must 

 think of what he intends to convey and let the words take care 

 of themselves. 



Lower down Dr. Benthall quotes Dr. Lewis Robinson, who 

 says : " The horse roamed in a wild .state, over plains of more 

 or less long grass and low bushes. When a horse is alarmed 

 he throws up his head to get as wide a view as possible. The 

 cow, on the other hand, keeps her head low, as if to peer under 

 the boughs which covered the marshy grass of her jungle home.'' 

 Cases of terror are only occasional occurrences amongst domesti- 

 cated animals, but in the wild state the necessity of caution in 

 the first movements on awakening from sleep, for fear of attack 

 by some lurking foe, is evident. Now when a horse rises he 

 gets on his fore feet and lifts his head high, whilst the cow 

 rises on her hind legs first and keeps her head low. The 

 horse being rfSturally a timid animal and rather unv^eildy in 

 the process of getting on his legs has learned to sleep mostly 

 standing and so be ready to move off at once, or kick as re- 

 quired ; hence a stableman always speaks to a horse before 

 approaching him from behind to make sure that he is awake 

 and so unlikely to kick. Will. A. DixoN. 



Sydney, October 14. 



^ Does Man use his Arms in Locomotion ? 



The letter by Mr. Martin under this heading in your issue of 

 November 28 raises the two interesting questions, (i) whether 

 the swinging of the arms in walking and running .serves any 

 useful purpose as an aid to progression, and (2) whether this 

 movement is a vestige, as Mr. Martin suggests, of the progres- 

 sion on all-fours of man's ancestors. 



The following considerations may be of inteiest, though they 

 are probably not put forward for the first time. 



The movement of the legs in opposite directions in different 

 planes involves a reaction, in the form of a couple, upon the 

 trunk, tending to rotate it alternately in opposite directions 

 about a vertical axis. Th.at such a rotation does take place 

 normally, when the arms are at rest, can be seen if the latter are 

 folded upon the breast over a long light horizontal rod to .serve 

 as an indicator. This is very obvious when running. Now the 

 swinging of the arms, each in unison with the leg of the 

 other side, introduces an opposing couple which more or less 

 completely balances, about a vertical axis, the reciprocating 

 motion of the legs. The importance of the efficient " balanc- 

 ing " of the reciprocating and revolving parts of a railway 

 locomotive, if steady and economical running is to be obtained, 

 is well known. 



That children and even adults, when compelled to crawl 

 upon all-fours, naturally and unconsciously adopt the move- 

 ments of the limbs common with four-legged animals is generally 

 considered an indication that man has retained the instinct for 



NO. 1675, VOL. 65! 



this mode of progression, though the conditions for its adoption 

 may seldom occur. It .seems reasonable to suppose that the 

 swinging of the arms in walking and running is a modification 

 of this in.stinct for a modified purpose. C. O. Bartrum. 



17, Denning Road, Ilampstead, N.W., November 30. 



Folklore about Stonehenge. 



I HAVE been waiting for more able pens than mine to corro- 

 borate Rev. Osmond Fisher's letter on the ciilhes lapidiint in a 

 recent issue of Naiuke. 



The same tradition about a loaf being placed on each stone 

 to facilitate counting occurs in other places where s.arsens have 

 been objects of reverence in bygone ages. In April, 1895, 

 Mr. Albany F. Major (hon. sec. Viking Club) and myself went 

 on a visit to Kits Coity House above Aylesford, Ivent. M. the 

 foot of Blue Bell Ilill on the way to Kits Coity there are a 

 number of sarsens in a field. On inquiring of a rustic as to 

 their whereabouts, in directing us to them he informed us that 

 a baker had made a bet he would count them and placed a loaf 

 upon each stone in order to count them correctly. This is a 

 slight variant of Mr. Fisher's statement about Stonehenge, but 

 the underlying idea is the same. R. AsHlNGTO.v BULLEN. 



The Vicarage, I'yrford, Woking. ^ 



PRESERVATIVES AND COLOURING 

 MATTERS IN FOOD. 

 'T^HE report of the Departmental Committee upon this 

 -'■ subject was issued last week and will be assuredly 

 welcomed by all interested both in the public health and 

 also in the trades concerned. The work of the Com- 

 mittee has been noticed at length in the lay Press and 

 we think, speaking generally, has given satisfaction. 

 Here we shall refer more particularly to the scientific 

 aspects of the report. The Committee was practically a 

 committee of experts, and we venture to think this 

 precedent might be followed more frequently in the 

 appointment of committees upon kindred subjects ; trade 

 interests are safe in the hands of impartial experts, and 

 the exclusion of the trade from a coinmittee of the kind 

 saves time and, we think, also tends to the attainment of 

 a most important desideratum, viz. unanimity. 



For some time past there has been a large and 

 apparently influential party of alarmists with regard to 

 the use of preservatives. These have all been heard at 

 length by the Committee which has just reported. Their 

 evidence consisted for the most part of elaborate a priori 

 argument, in support of which the most profound erudi- 

 tion was occasionally produced ; but, as the report politely 

 says, the opinion expressed was not always based directly 

 upon fact. In fact, if an in(|uirer turns the 500 pages of the 

 Blue book over in search of unequivocal instances of injury 

 to health from preservatives or, indeed, colouring matters 

 in food he will be lucky if he finds a single one. There 

 is no doubt some difficulty in fastening definite injury 

 upon so subtle a cause, especially since heretofore the 

 presence of preservatives has not even been declared. 

 Yet, nevertheless, for the last two years practically the 

 whole medical profession has been well alive to pre- 

 servatives in food being a possible source of injury to 

 health, and yet no definitely ascertained case, or practi- 

 cally none, has been forthcoming. Upon such data 

 it is obvious that the prohibition of preservatives 

 en musse was out of the question, and the recom- 

 mendations of the Committee practically resolve them- 

 selves into the regulation and control rather than 

 the prohibition of preservatives. There are, how- 

 ever, two exceptions to this ; formaline or formic 

 aldehyde is jjrohibited altogether, and all preservatives 

 and colouring matters are prohibited in milk. The deci- 

 sion with regard to formic aldehyde might strike the casual 

 observer in that nowhere in the report is it directly stated 

 that this substance in the quantities necessary is injurious 

 to health ; a peculiar difficulty, however, arises with 

 regard to it, viz., the practical impossibility of quantita- 

 tive control. It is obvious that a substance of such 



