6y 



NA rURE 



[Feb. 13, 1890 



These experiments show — 



(i) that 3 millimetres of glass and 10 centimetres of water 

 transmit a small portion of the non-luminous radiation of an 

 Argand gas-burner, but that, when the thickness of the water 

 is increased to 15 centimetres, the transmitted radiation consists 

 exclusively, or almost exclusively, of those kinds of radiation 

 which affect the eye as light. 



(2) That, with the form of apparatus employed (a thermopile 

 and galvanometer), there is no measurable difference between 

 the diathermancy of pure water and of a solution of alum. 



(3) That the radiation from an Argand gas-burner consists of 

 about 175 per cent, luminous and 98'25 per cent, non-luminous 

 radiation. 



January 30. — " On outlying Nerve-cells in the Mammalian 

 Spinal Cord." By Ch. S. Sherrington, M.A., M.B., &c. 

 Communicated by Prof. M. Foster, Sec. R. S. 



Gaskell has shown that in the cord of the alligator scattered 

 nerve-cells are to be seen at the periphery of the lateral column. 

 Although nerve-cells appear to be absent from that position in 

 the spinal cord of Mammalia as represented by the rabbit, cat, 

 dog, calf, monkey, and man, yet there are in these animals 

 isolated nerve-cells present in the white matter of the cord, not 

 only in the deeper portions of the lateral column, but in the 

 anterior and posterior columns as well. 



In the anterior columns occasional nerve-cells, of the multi- 

 polar kind, lie among those fibre-bundles which pass between 

 the deeper mesial border of the anterior horn and the anterior 

 commissure at the base of the anterior fissure. They, in the 

 instances observed, are smaller than the large cells characteristic 

 of the anterior horn, and lie with two of the processes directed 

 parallel with the horizontal transverse fibres among which th;^y 

 are placed. 



In the lateral column, of the spinal cord of man and the 

 other animals named above, it is common to find outlying 

 members of the group of small cells of the lateral horn, Clarke's 

 tractus intermedio-lateralis, situated in the white matter, dis- 

 tinctly beyond the limits of the grey. Some outlying cells here 

 are placed at a great distance from the grey. They are gener- 

 ally placed upon, or at least in close connection with, the fine 

 •cinnective-tissue septa which pass across the white matter. It 

 is probable that the cells are connected with the medullated 

 nerve-fibres running along these septa. 



In the part of the lateral column adjacent to the lateral 

 reticular formation numerous nerve-cells are to be found among 

 the interlacing bands of nerve-fibres. These are often fusiform, 

 l)Ut in many cases multipolar ; they are for the most part small, 

 but occasional large individuals can be found ; the latter would 

 appear always to be multipolar. Where the lateral column 

 comes into contact with the lateral limb of the substantia gela- 

 tinosa of the caput cornu posterioris ganglion-cells can frequently 

 be seen in it. The larger axis of these cells is parallel to the 

 outline of the caput cornu. 



In the posterior columns outlying nerve-cells are also to be 

 found, especially in the human cord. They are best seen in the 

 upper lumbar and lower dorsal regions. They are large, 

 measuring in some instances 70 ix across. In appearance they 

 closely resemble the cells of Clarke's column. They are nearly 

 always of broadly ovate shape. They appear always to lie on or 

 in close relation to those horizontal bundles of nerve-fibres 

 which curve in a ventro-lateral direction from the depth of the 

 extero-posterior column into the grey matter in the neighbourhood 

 •of the posterior vesicular group. The longer axis of the cell is 

 placed parallel to the nerve-fibres it lies upon or among. 

 Where a process from the bipolar cell-body can be followed, it 

 disappears in a direction which is that of the surrounding nerve- 

 fibres. 



With regard to the cells existing among fibres passing to the 

 white commissure of the cord, it is legitimate to consider their 

 presence as evidence in favour of the view that some of the cells 

 ■of the median portion of ihe ventral grey horn are directly con- 

 nected with medullated fibres passing to or from the opposite 

 half of the cord by way of the anterior commissure. 



The cells in the lateral column outside the lateral horn may 

 be taken to point to the connection of the intermedio-lateral 

 group of Clarke with the nerve-fibres which radiate in bundles 

 from the grey matter of that region into the lateral column. 

 Concerning some of the outlying cells in the more dorsal portion 

 of the lateral column, the same inferences may be drawn ; and 

 some of them would seem to be connected with fibres of the 

 posterior roots that curve round the lateral aspect of the caput 



cornu posterioris. Of the outlying cells in the posterior column, 

 if they are outlying members of Clarke's group, the relations 

 which they suggest for that group are — 



i. That the group is connected directly with certain of the 

 median fibres of the posterior spinal roots — namely, those which 

 after an upward course in Burdach's column plunge into the grey 

 matter of the base of the posterior horn. 



ii. That some at least of the cells of that group are inter- 

 polated, more or less immediately, into the course of medullated 

 nerve-fibres of large calibre. 



The question naturally arises, May not these cells in the 

 posterior column of the Mammalian cord represent the bipolar 

 cells discovered by Freud, in the cord of Petromyzon planeri, to 

 be in direct communication with fibres of the posterior roots? 

 If so, may Clarke's column be considered a portion of the 

 ganglion of the posterior spinal nerve-root which has been 

 retained in the interior of the spinal cord in the thoracic an 1 

 certain other regions ? 



Royal Meteorological Society, January 15. — Annual 

 Meeting. — Dr. W. Marcet, F. R.S., President, in the chair.- — 

 The Council, in their Report, congratulated the Fellows on the 

 generally prosperous state of the Society ; the past year's work, 

 though not in any respect exceptional, having been thoroughly 

 successful. The total number of Fellows is 550, being an in- 

 crease of 25 on the previous year; the finances are improving, 

 and the library is overflowing. — Mr. Baldwin Latham wa-i 

 elected President for the ensuing year. — The retiring President, 

 Dr. Marcet, then delivered an address on "Atmospheric Dust," 

 which he divided into organic or combustible, and mineral or in- 

 combustible. The dust scattered everywhere in the atmosphere, 

 and which is lighted up in a sunbeam, or a ray from an electric 

 lamp, is of an organic nature. It is seen to consist of countless 

 motes, rising, falling, or gyrating, although it is impossible to 

 follow any of them with the eye for longer than the fraction of a 

 second. It is difficult to say how much of the dust present in 

 the air may become a source of disease, and how much is inno- 

 cuous. Many of the motes belong to the class of micro- organisms 

 which are frequently the means of spreading infectious diseases. 

 Many trades, owing to their dusty nature, are very unhealthy. 

 Dust, when mixed with air, is inflammable and liable to explode. 

 After giving several instances of explosions due to fine dust in 

 flour mills and coal mines. Dr. Marcet referred to inorganic or 

 mineral dust, and gave an account of dust storms and dust 

 pillars in India. He then proceeded to describe volcanic dust, 

 which consists mainly of powdered vitrified substances, produced 

 by the action of intense heat. The so-called ashes or scoriae shot 

 out in a volcanic eruption are mostly powdered pumice, but they 

 also originate from stones and fragments of rocks, which striking 

 against each other, are reduced into powder or dust. Volcanic 

 dust has a whitish-gray colour, and is sometimes nearly quite 

 white. Dr. Marcet concluded with an account of the great 

 eruption of Krakatab in August 1883. The address was 

 illustrated by a number of lantern slides. 



Edinburgh. 



Royal Society, January 20. — Sir W. Thomson, President, in 

 the chair. — Prof Tait communicated an obituary notice of Dr. 

 Andrew Graham, R.N., by Mr. John Romanes, W. S. — The Pre- 

 sident gave a paper on electrostatic stress. A complete dynamical 

 illustration of electro-dynamic action may be had in an elastic 

 solid, homogeneous in so far as rigidity is concerned, permeated 

 with pores of unalterable size containing liquid. These pores 

 may be in part in communication with each other, and in part 

 closed by elastic partitions. These cases correspond to con- 

 ductors and non-conductors respectively. Electrostatic stress 

 depends on the curvature and extension of the partitions. The 

 law of capacity in the model is identical with that in conductors. 

 — Prof. C. Michie Smith described the great eruption at Ban- 

 daisan, Japan, photographs being shown. — Prof Tait read a 

 paper, by Prof Heddle, on a curious set of fog-bows. — Dr. 

 Berry Haycraft gave an account of some experiments which 

 extend our knowledge of volitionary movement and explain the 

 production of the muscle and heart sounds. 



Paris. 



Academy of Sciences, February 3.— M. Hermite in the 

 chair. — On the nuclei of the great Comet II. of 1882, by M. F. 

 Tisserand. From the presence of five bright points disposed in 

 a straight line, it is evident that the matter was not uniformly 



