302 



SCIENCE. 



been distilled several times can remain exposed to the air 

 for six or eight days without the slightest augmentat'on 

 of resistance, in regard to the needle, being apparent. 

 Besides, in the measures taken with distilled water, the 

 entire preparation of the experiment from the moment 

 when the liquid was poured into the capsule until the 

 needle, was left to itself, occupied but five minutes ; then 

 during the ten partial measures afterward effected, no 

 increase of resistance was observable. Could particles 

 of dust floating about in the atmosphere produce an 

 effect during those five minutes? Is it admissible ? In- 

 deed, M. Hagen has shown us conclusively that the 

 superficial tension of distilled water decreases perceptibly 

 when the liquid is exposed to the air ; but this diminution 

 is gradual and continued, and in order to produce any 

 visible effect requires several hours The peculiar fact 

 M. Hagen describes, therefore, appears to me to bear no 

 relation whatever to the resistance shown to the needle's 

 movements; and inasmuch as air on the other hand, 

 exercises no chemical action upon distilled water, and 

 moreover as we are 'unable to invoke the influence of 

 particles of atmospherical dust, we are led to attribute 

 the fact established by M. Hagen to a cause arising from 

 the interior of the liquid. 



Now, in reference to the actual state of the case, I 

 shall say again that it is useless to have recourse to a 

 coating of dirt whose existence we cannot account for, 

 and also that it is much more simple to admit the pres- 

 ence of an atomic organization peculiar to the superficial 

 layer of the liquid. 



As far as M. Van der Mensbrugghe's theory is con- 

 cerned, M. Marangoni expresses himself in the following 

 manner : 



" The mass of the liquid effectually diminishes the 

 variations of temperature produced upon the surface, 

 which, in its turn, also decreases the variations of ten- 

 sion ; in ordinary cases the latter are but trifling when 

 compared with the variations attributed to dirt." 



According to this remark, we should believe that the 

 surface of the saponaceous solution, which, M. Marangoni 

 states, possesses an undeniable coating of dirt, resists 

 the movements of the needle more forcibly than the dis- 

 tilled water which could have hardly any dirt on its sur- 

 face. In my experiments however, directly the opposite 

 of this has occurred. The ratio of time required for the 

 needle to describe an angle on the surface and beneath 

 it when distilled water was used was, i, 92, while when 

 soap was used it was but 1. 82. 



M. Van der Mengsbrugge's theory certainly deserves 

 some attention in regard to the phenomena >n question ; 

 but owing to the above remark of M. Marangoni, and 

 the considerable dimension of the needle, relatively 

 speaking, we may be permitted to doubt that any notable 

 effect can result from it. Besides, if it did, we should 

 find it again in those liquids of weak tension which do 

 not produce bubbles, that is to say, alcohol, spirits of 

 turpentine, olive oil, etc.; at least we should be able to 

 observe a feeble rotation of the entire surface ; now, this 

 is by no means authenticated. 



Finally, before attributing these phenomena to any 

 other cause than that of a peculiar viscidity of the outer 

 coating, it would be necessary to refute those arguments 

 which have led me to the conclusion that the superficial 

 coating of liquids possesses more atomic mobility than 

 the interior portion. M. Marangoni is perfectly silent in 

 regard to this part of my work. 



After this examination of M. Marangoni's theory how- 

 ever, I Consider myself justified in maintaining my opinion; 

 but I forego all ulterior discussions referring to the sub- 

 ject, and leave all those physicists who may be interested 

 in the question, to compare for themselves M. Marang- 

 oni's writings with mine, and to try to discover, if pos- 

 sible, which of us is right. 



ON THE STRUCTURE OF THE ORANG 

 OUTANG. 



By Henry C. Chapman, M. D. 



From the paper on this subject in the Proceedings of 

 the Academy of Natural Sciences, of Philadelphia, we 

 take the following facts : 



The subject dissected was a young male Orang Outang 

 {Simia Satyrus), about three years old. The first thing 

 to strike Dr. Chapman was the length of the upper ex- 

 tremity, it being three inches longer than the lower one, 

 agreeing nearly in this respect with the Gorilla, the differ- 

 ence in the extremities of that animal being 3^ inches, 

 whereas in the Chimpanzee a difference of 1 % inches onlv 

 was found. The foot in the Orang, however, was Yz 

 inch larger than the hand, whereas in the Gorilla the hand 

 was y z inch larger than the foot ; in the Chimpanzee the 

 difference in this respect.was ^-in. in favor of the foot. In- 

 deed, the distinctness of hand and foot superficially is 

 more marked in the Gorilla than in the other anthropoids. 

 The same facial muscles are found in man and the Orang 

 Outang, with the exception that there is but one zygoma- 

 ticus, possibly corresponding to the zygomaticus minor of 

 man. The facial muscles, however, are not differentiated as 

 in man, rather hanging together. The upper extremity of 

 the Orang, in its muscles, differed essentiallyfrom that of 

 man in the absence of the flexor longus pollicis, and ex- 

 tensor primi internodii pollicis and in the presence Q r 

 the additional tendons to the ring and middle fingers 



The Orang agreed with the Gorilla in not having a 

 flexor longus pollicis, but disagreed with it in having the 

 pronator radii teres, arising by two heads in the presence 

 of a palmaris longus, in the additional teudons for ring 

 and middle fingers, and in not having the extensor primi 

 internodii pollicis. 



As compared with the Chimpanzee, the Orang agreed 

 in reference to the pronator radii teres and palmaris 

 longus, but in the absence of the fltxor longus pollicis as 

 a slip from the profundus, and in the presence of the ad- 

 ditional extensor tendons it differed. 



Dr. Chapman differed from Bischofl", Owen, Huxley 

 and others, in seeing no essential difference between the 

 scaiisorius, of Traill, and the glutseus minimus in man, 

 an opinion, it appears, which had been previously ex- 

 pressed by Prof. Barnard in 1876. 



The leg and the foot of the Orang, as compared with 

 man, differed in the absence of the peroneus tertius, plan- 

 taris, flexor longus hallucis and transversus pedis, in the 

 fibular origin of the soleus, and in the presence of the 

 external origin of the accessorius only, in the distribution 

 of the perforating and perforated tendons of the toes, in 

 the interossei, and in the presence of an opponens for 

 the big toe. In this latter respect, the Orang differs not 

 only from man, but from all the other monkeys and 

 anthropoids, the foot having a very hand-like appearance, 

 as compared with that of the Gorilla and Chimpanzee. 

 The foot of the Orang differs further in the absence of a 

 special flexor for the big toe. This is supplemented, to 

 a certain extent, by the opponens, and in a partly devel- 

 oped accessorius. 



If Professor Huxley's canon can be accepted that tue 

 distinction between a hand and a foot consists in the latter 

 possessing tarsal bones, the peroneus longus and brevis, 

 the short extensor and short flexor muscles, then the pos- 

 terior extremity of the Orang terminates in a foot. 



Dr. Chapman, however, appeared to think that the dif- 

 ference between the hand and the foot in Man, the Gorilla, 

 and Chimpanzee, and the lower monkeys, is greater than 

 that observed between the corresponding members of the 

 Orang. 



It is usually stated that the uvula is absent in the Orang, 

 and on looking into the mouth, at first sight this appears 

 to be the case, as it does not hang down as in man, be- 

 tween the pillars of the fauces, Nevertheless, Dr. Chap- 



