SCIENCE. 



[Vol. XIII. No. 33 



beautiful white streal< ran perpendicularly from the ice to the bot- 

 tom, where it recurved, and finally disappeared in thin filaments. 

 It was discovered that this was due to camphor-smoke purposely 

 introduced. No appearance with ice was noted in dust-free air. 



Experiment d,. — Nearly saturated air, with a little smoke, was 

 compressed, and suddenly released from pressure. A haze filled 

 the whole bottle. 



Experiment 5. — On repeating this again and again, occasionally 

 introducing a little smoke, it was found that the degree of satura- 

 tion made little difference. Finally the haze was produced in air 

 having a relative humidity of two per cent andadewpoint of —21°, 

 the outside air being at about 80°. 



Experimetit 6. — The bottle was filled full with water, removing 

 every particle of air. All the dust-particles were driven from the 

 compressor, and by it the water was forced out with air nearly 

 saturated. On compressing this air, absolutely dust-free, and re- 

 leasing it, a beautiful mist of clearly rounded water-particles was 

 noted. The appearance was very different from the cloud-haze 

 before noted, which had no rounded particles, but was an indefi- 

 nite white haze. The difference between the two could not for a 

 moment be mistaken. 



Experiment J . — On introducing a little smoke, the haze was 

 very prominent at first ; but, after a few compressions, the haze be- 

 gan to disappear, and there were seen together both haze and mist. 

 The haze was finally entirely sifted out, but repeated compressions 

 and expansions failed to change the mist in any way. 



Experiment 8. — Dust-free air, nearly saturated, was suddenly 

 expanded by an air-pump, and the mist appeared as before under 

 compression, but was much shorter lived. No. 7 was also repeated 

 with the air-pump, but the effects in all cases were less marked 

 than under compression. It appeared in the air-pump experiment 

 as though the mist formed at the top of the bottle, and it was 

 feared that there might possibly be a leakage around the stoppers 

 or tubes. This led to No. 9. 



Experiment 9. — The bottle was filled full and inverted, great 

 care being taken that not a particle of dust should get in. A little 

 water was left at the bottom, and this formed a most effectual stop 

 for all ingress of air. The air-pump gave the same mist as be- 

 fore. 



The following are the proofs that the mist was formed in nearly 

 saturated air without the intervention of solid particles of any kind : 

 I. The haze from dust or smoke was entirely different from the 

 mist in dust-free air ; 2. It was a very easy matter to sift out the 

 smoke-haze by repeated compressions, but not so the mist ; 3. 

 The mist was the same so long as the compression and saturation 

 remained constant (it was impossible to diminish this after hours 

 of labor) ; 4. The mist settled down to the bottom after each com- 

 pression, and finally moistened it with drops, showing that an 

 enormous number of mist-globules had settled. If each mist- 

 globule had taken a dust-particle along, it is easy to see that after 

 a very short time every mote would have been deposited. 



Conclusions. — i. It seems practically impossible to perfectly 

 saturate air by cooling, by expansion, by mixture of cold and warm 

 air, by passing through wet substances, or in any analogous man- 

 ner. 2. This is probably the reason that no permanent haze cloud 

 or mist has yet been formed by direct experiment. 3. Cooling by 

 expansion or in any other way, and consequent condensation, is 

 not needed to display invisible smoke or moisture particles. 4. 

 The mixing of two bodies of air of widely different temperature, 

 and nearly saturated, will not produce a cloud. 5. The sudden 

 cooling of nearly saturated air will not produce a cloud. 6. A ve- 

 locity of one hundred and more miles per hour of an ascending 

 current will hardly suffice to produce cloud or mist by expansion in 

 nearly saturated air. 7. It seems possible to unite smoke particles 

 so as to form visible haze in dry air. This may be a mechanical 

 aggregation due to a violent bombardment of the particles on sud- 

 den expansion. 8. The same statement may be made of moisture- 

 particles in nearly saturated air. 



Some of these conclusions are very remarkable, and I sincerely 

 trust that other experimenters will make the few simple trials 

 needed. To one having access to a laboratory the whole expense 

 will be practically nothing. H. A. Hazen. 



Washington, June ii. 



Osteological Notes. 



Professor Flower, in his admirable hand-book on the osteol- 

 ogy of the Mammalia, lays special stress on the disposition of the 

 lateral bones of the cranium as constituting points of difference be- 

 tween the Catarrhini and Platyrrhini, the Old and New World 

 monkeys. 



On careful examination of the skulls in this museum in reference 

 to this subject, I find that there are exceptions to almost every rule, 

 that might be offered, and that authorities differed even on these 

 exceptions. Notwithstanding these differences, however, it may be 

 affirmed that (i) the Catarrhini, as is the rule in man, have the 

 alisphenoid join suturally with the parietal and frontal, with one or 

 both, or they may have the squamosal join with the frontal ; (2) the 

 Platyrr/iijii have the parietal and malar join suturally, thus pre- 

 venting the union of the alisphenoid with the parietal and frontal, 

 or of the union of the squamosal with the frontal. 



It is generally taught that the os planum of the ethmoid enters 

 into the formation of the inner wall of the orbit in man and apes 

 only. Gegenbaur, on this point, says, " Except in some Edentata, 

 it is in the Primates only that a portion of the lateral surface 

 reaches to the median boundary of the orbit, where it forms the 

 lamina papyracea." The great anatomist overlooks the Felida in 

 the order of the Carnivora, in many of which family, as in the 

 domestic cat {Felis domestica), in the tiger {Felis tigris), in the 

 jaguar {Felis oncd), and in the lion {Felis led), as well as in several 

 of the ViverridcE, the os planum is distinctly visible in the wall of 

 the orbit. 



The perforation of the transverse processes of the seventh cervi- 

 cal vertebra by the vertebrarterial canal, as also the presence of an 

 articular cavity on the hinder edge of the body of this same verte- 

 bra for the reception of the head of the first rib, are distinctive 

 characters in some of the orders of the Mammalia, and consider- 

 able importance has been laid upon their presence or absence in 

 the matter of classification. 



Seventh Cervical Vertebra, 



Gorilla 



Hylobates ^. . . 



Ungulata ^ 



Proboscidia. . 



Chiroptera. .. . 

 RodentiaS.... 



Edentata' 



Marsupialia — 

 Monotremata ^ 



Imperfectly developed 

 Imperforate 



Absent. 

 Present, 



Absent. 

 Present. 



imperforate condition of the transve: 

 \ much. Mivart says that he, has nei 

 achyitriis, Nyctipitkecics, Chrysothr 



1 In the other primates the perforate 

 process of the seventh cervical vertebra vi 

 seen it perforated in Hylobatss, Mycetes, 

 Hapale, Lciiiiir, Galago-arctocebtts. 



^ The giraffe has the seventh cervical perforated. 



^ Lepiis has the seventh cervical perforated. 



' In the Sloths the three-toed has the eighth cervical perforated, and the two-toed, 

 the sixth cervical. 



5 The Echidna has the seventh cervical imperforate, and the OrnithorhyKchus 

 has an articular cavity for first rib on the same. 



The above table, based upon an examination of the articulated and 

 disarticulated skeletons in this collection, may prove serviceable to 

 those interested. D. D. Slade. 



Mus. Comp. Zool., Cambridge, Mass., June 12. 



