lO 



NATURE 



\_Nov. 4, iSSa 



face. The accompanying tracings from Catherwood's work will 

 sufficiently explain my meaning. 



Fig. I, from the gateway at Labnah, pi. xix. ; Fig. 2, from 

 the gateway of the great Teocallis Uxmal, pi. xii. ; Fig. 3, from 



Fig. 2.— Gateway of the Great Teocallis Uxmal (Plate 12). 



Las Monjas Chichen Itza, pi. xxi., illustrate the development of 

 the fret. Fig. 4, from Las Monjas Chichen Itza, pi. xxi., shows 

 another modification of the human face. 



In his "Grammar of Ornament" Owen Jones says (p. 35) : 

 ' ' In Mr. Catherwood's illustrations of the architecture of Yucatan 



Fig. 3. — Las Monj 



(Plate 21). 



we have several varieties of the Greek fret : one especially is 

 thoroughly Greek. But they are, in general, fragmentary like 

 the Chinese." The reason I would assign for this "fragmentary" 

 natrre of the design is that it w as just parsing from the disjointed 

 ornament to the pattern stage. An examination of the plates 



Fig. 4. — Las Monj; 



(Plate : 



will prove the profuse employment of tlie more or less grotesquely 

 modified human face in mural decoration. 



The hypertrophy of one set of organs, with the atrophy of 

 another, and modification of a third, are paralleled in the 

 specialisations of all degraded forms. Alfred C. Haddon 



Zoological Museum, Cambridge 



Temperature of the Breath 



I AM unable to see what bearing "I. J. M. P.'s" suggestion 

 that I should try the effect of dipping my thermometer, enve- 

 loped in a tightly-rolled handkerchief, in water at 108° has on 

 this subject. Every one of course knows that a thermometer in 

 such circumstances would eventually acquire the temperature of 

 the water in which it is immersed. 



The state of the matler is simply this: On the one hand 

 w orks on physiology agree in stating that the normal temperature 

 of the breath is from 95° to gy", and that of the interior of the 

 body from 98°'5 to 99'"'S. These are what Mr. McNally would 

 call "ascertained physiological truths." On the other hand I 

 lind that by breathing on the bulb of a thermometer enveloped 



in about twenty folds — more or less — of a silk, cotton, or woollen 

 cloth for five minutes, the thermometer indicates temperatures 

 varying — owing to conditions not yet precisely ascertained — 

 from 102° to ioS°, which, as every one knows, are temperatures 

 vastly greater than the accepted temperature of the breath or 

 interior of the body. 



There is no question of squeezing up the reading of a delicate 

 thermometer by the tightness of the enveloping material, for the 

 thermometer used in these experiments is an ordinary clinical 

 thermometer, such as I use daily in practice, the bulb of which 

 is made of such stout glass that no amount of pres-ure short of 

 breaking the bulb will move the mercury in the slightest degree. 



The following variation in the mode of experimenting precludes 

 the possibility of any pres-ure on the thermometer. I put the 

 thermometer in a glass tube about three-fourths of an inch bore, 

 open .at both ends, packed the stem loosely with cotton wool, 

 but left the bulb free at one end of the tube. I then enveloped 

 the whole in a silk handkerchief and breathed through twelve 

 folds of the material into the end of the tube where the bulb of 

 the thermometer was, untouched by cotton wool, glass tube, or 

 silk handkerchief After five minutes the thermometer showed 

 a temperature of I02°. In this case, and I believe also in my 

 former experiments, the enveloping material merely acted as a 

 bad conductor, retaining the heat produced by the breath. 



As any one can easily repeat these experiments for himself, I 

 would suggest to your correspondents that they should do so. 

 When the facts have been established by reiterated experiments 

 — my own observations have been corroborated by several of my 

 friends — the explanation or significance of them will no doubt 

 be speedily arrived at. Provisionally I suggest that these 

 observations show respirUion to be a powerful agent for getting 

 rid of the superfluous caloric of the body. 



How is this heat communicated t-o the breath? If it had 

 anything to do with the conversion of the carbon of the blood 

 into carbonic acid, the quantity of carbonic acid passed off by 

 the breath would be greater when the temperature of the latter 

 is higher, less when it is lower. But Letellier's experiments 

 show that the amount of carbonic acid exhaled is greatly 

 increased by externa'l colJ, and diminished by heat ; whereas my 

 experiments apparently show that the temperature of the breath 

 is lower in external cold, higher in heat. 



To solve the questions suggested by these experiments one 

 would require the aid of a physiological laboratory, but as that 

 is not at my command, and, moreover, as I could not devote 

 the necessary time to them, I must leave their solution to others. 



October 20 R. E. Dudgeon 



Soaring of Birds 



I BEG to send you some data on the above subject, as I live 

 where the phenomenon is of daily occurrence. Most of the 

 large birds out here soar, i.e. can circle round and round without 

 flapping the wings, and also can r/Kthus from 100 or 200 feet to 

 some 8,000 by same means. The pelican, the adjutant, and several 

 large birds allied to it, the vulture and the cyrus, rise thus. 



Firstly they rise by flapping the wings vigorously, and when 

 up some 100 or 200 feet, if there is a breeze, begin to soar in 

 large circular sweeps, rising 10 to 20 feet at each lap, the whole 

 bird being otherwise quite motionless, and the wings extended 

 rigidly. 



We have two steady winds here, from north-east and west- 

 south-west, and in one of these the birds rise to great heights, 

 and can be seen as small specks up in the blue, and watched 

 with telescope, going round and round, motionless otherwise. 

 The following data are trustworthy : — The birds weigh from 20 

 to 40 lbs. ; spread of wings, 10 to 12 feet ; stand 3 to 5 feet 

 high ; speed flying or soaring, about ij to 35 miles per hour 

 (estimated). 



They rise by flapping the wings. If there is no wind they 



j ^ \ soar ; they generally begin to soar at 100 to 200 



feet elevation when above the level of the forest. In soaring they 



\ do not j „o in a right line, but in large curves of a spiral' 

 ( cannot ( fa « ' 



that leans to leeward. 



At each lap they can rise 10 to 20 feet, but lose position 

 laterally of 20 to 50 feet to leeward. The soaring can go on. 

 without once (lapping the wings, till the bird is almost out of 

 sight. 



If near, the feather-tips make a loud musical "sing," and 

 the pre, ence often first known by it. If watched, they come 



