July 31, 1885.] 



SCIENCE. 



83 



January, February, and March are bright yellow; 

 upon a second question, ' shining white yellow,' 



April is blue, 'the shade ladies call French blue.' 



May, light yellow, 'not at all like January.' 



June, bright green. 



July is glaring yellow; and August, orange. 



September is golden brown ; October, dark brown. 



November is 'indiscriminate gray. I cannot exact- 

 ly describe it: it is like lead color.' 



December is gray. 



This case appears to me suflniciently different from 

 any of those mentioned by Galton to deserve special 

 notice. 



It would be very desirable, I think, to make a sys- 

 tematic investigation of the influence of heredity on 

 such associations of color and form. Could not the 

 Psychical society undertake such work ? 



Charles S. Minot. 



Boston, July 22. 



Maxwell's demons. 



Sir William Thomson has shown that since work 

 is readily converted into heat, while heat is never 

 wholly transformed into work, or in fact into any 

 other form of energy, there must continually take 

 place what Tait calls a degradation of energy ; while 

 its dissipation is pronounced to be the inevitable 

 consequence of certain laws, connecting heat and 

 work, established by thermodynamics. 



Maxwell has pointed out that one of these laws is 

 by no means a necessary truth [' Theory of heat,' 

 chapter xxii.. Limitation of the second law of 

 thermodynamics]. Theory shows, that, in what is 

 called a state of uniform temperature, some of the 

 molecules of a body have by chance much greater 

 velocities than others. If, therefore, as Maxwell 

 says, we could suppose the existence of small beings, 

 capable of following the motion of each molecule, 

 and opening or shutting holes in a partition so as to 

 allow the fastest molecules to pass through one way 

 and the slowest the other, it might be possible theo- 

 retically, without expending any work, to separate a 

 gas into two portions, — one hot and the other cold, — 

 in contradiction to the second law of thermodynamics. 



It seemed to me of interest to point out that what, 

 as Maxwell has shown, could be done by the agency 

 of these imaginary beings, can be and often is actu- 

 ally accomplished by the aid of a sort of natural 

 selection. 



When the motion of a molecule in the surface of a 

 body happens to exceed a certain limit, it may be 

 thrown off completely from that surface, as in ordi- 

 nary evaporation. Hence in the case of astronomi- 

 cal bodies, particularly masses of gas, the molecules 

 of greatest velocity may gradually be separated from 

 the remainder as effectually as by the operation of 

 Maxwell's small beings. 



It is true, that, in overcoming the attraction of the 

 central mass, the escaping molecules may be deprived 

 of-the whole or a portion of their velocity; but the 

 transformation of heat into work marks the process 

 still more distinctly as an exception to the second 

 law of thermodynamics, which " asserts," according 

 to Maxwell, "that it is impossible to transform any 

 part of the heat of a body into mechanical work, ex- 

 cept by allowing heat to pass from that body into 

 another at a lower temperature" ['Theory of heat,' 

 chapter viii.]. 



One might now dismiss the subject as a mere curi- 

 osity; but is it not possible that what may be called 

 the renovation of energy plays an important part in 

 the history of the universe ? While philosophers, 

 anxious to preserve their store of available energy, 



may speculate on the possible equivalence of renova- 

 tion and dissipation, will not the scientist hesitate, 

 without further examination, to extend the principle 

 of universal dissipation from physical to astronomi- 

 cal phenomena ? Harold Whiting. 



The classification and paleontology of the 

 U. S. tertiary deposits. 



In penning my protest {Science, June 1^) against 

 some recent geological and paleontological specula- 

 tions of Dr. Otto Meyer, I had intended that it should 

 represent my final words in the matter, inasmuch as 

 the article under discussion appeared to me unworthy 

 of exhaustive criticism. The appearance of instal- 

 ment No. 2 of the same series (which, if any thing, is 

 only more remarkable than No. 1), and a rejoinder 

 to the first from Prof. E. W. Hilgard, constrain me to 

 add a few additional paragraphs, more, perhaps, of a 

 general than of a special character. 



Professor Hilgard says, "I emphatically agree with 

 Heilprin as to the impossibiliLy of subverting the 

 cumulative stratigraphical evidence to the effect that 

 the relative superposition of the several principal 

 stages — the Burstone, Claiborne, Jackson, and 

 Vicksburg groups — cannot be otherwise than as 

 heretofore ascertained;" and, further, "I recall to 

 my mind that years ago I had occasion to repel a 

 similar attempt, on the part of Mr. Conrad, to sub- 

 vert the relative position of the Jackson and Vicks- 

 burg groups upon supposed paleontological evidence." 

 It might appear, from the conjunction of these ex- 

 pressions, that the only evidence supporting the 

 accepted superposition of the different members of 

 the southern old tertiaries was of a stratigraphical 

 character, and that the paleontological evidence was 

 in confi.ict with that derived from stratigraphy. As a 

 matter of fact, however, the paleontological evidence, 

 whatever it may have been when Conrad first devised 

 his scheme of classification, is, as we now know it, 

 absolutely comfinnatory of the pregnant facts which 

 the stratigraphy of the region presents; and, indeed, 

 it would be difficult to find a region of similar depos- 

 its where it is more so. The absence or scarcity of 

 forms of a distinctively old-type facies in the Vicks- 

 burg beds, and the introduction there of new forms 

 whose equivalents or immediate representatives are 

 known only from the newer horizon, are sufficient in 

 themselves to establish the position. While it may 

 be true, although this is far from being proven, that 

 not a single one of the Vicksburg fossils is identical 

 with species belonging to the typical oligocene basin 

 of Germany, it is equally true that several of the spe- 

 cies find their analogues or equivalents in the deposits 

 of San Domingo, which are indisputably of post-eocene 

 age; and whatever Dr. Meyer's own individual opinion 

 may be as to the bugbear Orbitoides, and to its value 

 as a 'leitfossil,' the keen appreciation of Hautken, 

 Rupert Jones, Karrer, Fuchs, Suess, and Duncan has 

 long since settled the question. It is amusing to 

 have the forty-year old opinions of D'Orbigny and 

 Edward Forbes referred to as authority on the value 

 or no-value of certain fossil forms whose organiza- 

 tion was barely known at the time that the opinions 

 were rendered, and whose differences from other 

 (distantly) allied forms were not even dreamed of. 

 With singular perversity of purpose. Dr. Meyer fails 

 to inform his readei-s that the American foraminifer 

 whose merits are discussed by Professor Forbes, is 

 confounded by that naturalist with a form which be- 

 longs not only to a distinct genus and family from 

 Orbitoides, but to a distinct sub-order. 



Aside from the testimony of the Vicksburg fossils 



