Algust 17, 1905] 



NA TUAE 



389 



suffers somewhat in comparison with the New Jersey one 

 through faulty editing ; there are many more diagrams in 

 the former than in the latter work, but they are sometimes 

 too small for the matter they contain (p. 572) ; they are 

 rather untidy in appearance, and are frequently inserted 

 sideways in the text when they should be upright. The 

 chemical portion is unnecessarily duplicated, and the im- 

 portant table of analyses (p. 344) is rendered useless for 

 ready reference by the complete omission of silica. 



Botli books are provided with maps of the geological 

 distribution of the clays, with abundant photographic 

 illustrations of varying degrees of value, with a directory 

 of the clayworkers in the Estate, and fairly numerous refer- 

 ences to the fiterature of the subject. In each case the 

 section dealing with pottery is weak. 



Prof. Ries still maintains that the most generally useful 

 way of expressing the chemical nature of a clay is through 

 the ultimate analysis, though he admits the value of tne 

 so-called " rational " analysis in the case of the higher 

 grade clays; with this view we are entirely in accord. 

 Messrs. Beyer and Williams appear to lean somewhat 

 towards the " rational " analysis, and have given the 

 results in this form along with the ultimate analysis — a 

 useful custom. Their method of dividing the ultimate 

 analysis into "sand and clay," "total fluxes," and 

 "moisture, CO, and SO3," is convenient. The influence 

 of titanium on the fusibility of clay is rightly emphasised 

 by Kies ; in this country it has been very generally 

 neglected in analyses. 



ihe physical tests applied to clay products were ; — com- 

 pression tests, transverse tests, absorption tests, and 

 freezing and thawing (Iowa only) ; of these, the second is 

 held in highest esteem ; it is certainly far superioi- to the 

 crushing test in most cases, but we are among those who 

 do not agree with Prof. JMarston that for paving brick 

 it can take the place of the " rattler " test; the objections 

 he urges against the latter may be applied with equal 

 force to the former, while he admits that the action of 

 the " rattler " approximates more closely to the kind of 

 wear to which paving bricks are subjected in actuat use. 



From a multitude of councillors we expect wisdom ; it 

 is none the less true that if the councillors will not consult 

 one another we are apt to get only confusion. Everyone 

 who publishes some results of physical tests of clays and 

 clay wares seems to think that these should become 

 recognised standards at once. The two authorities here 

 cited are no exception ; each one stoutly believes that its 

 own favoured methods should be adopted for general use. 

 There is here a satisfactory unanimity as to the kind of 

 test required, but when we come to details of application, 

 we find considerable divergence of practice in precisely 

 those points which together go to constitute a standard 

 test. 



Thus in obtaining the modulus of rupture in the " trans- 

 verse " test of bricks, New Jersey employs rounded knife- 

 edge contacts alone, while Iowa interposes steel bearing- 

 plates between the brick and the knife-edges ; in the 

 crushing and absorption tests New Jersey uses half a 

 brick, Iowa grinds out from the brick a 2-inch cube ; 

 again, the former measures linear shrinkage and calculates 

 the cubic shrinkage, the latter reverses the process, using 

 a Seger volumeter for the purpose. Por estimating texture 

 (fineness of grain) Iowa employs a modification of 

 Whitney's method. New Jersey uses a centrifugal 

 apparatus. Further, there is an important difference 

 between the methods of collecting materials ; Prof. Marston 

 asks for a fairly large consignment to be sent by the 

 manufacturer, and tests twenty or more bricks in the 

 transverse way ; on the other hand, members of the New 

 Jersey Geological Survey staff pick out five to seven re- 

 presentative bricks on the spot, and send them to be 

 similarly tested by Prof. Ries. Useful though these tests 

 may be for local reference, it is evident that a standard 

 series of tests will never be arrived at by such isolated 

 endeavours ; indeed, we cannot help feeling that in these 

 and similar publications there is much duplication and 

 waste of energy through the lack of a little coordination. 



There will be diversity of opinion as to the expediency 

 of the State taking upon itself the task of publishing tests 

 of manufactured wares ; it stands in the same relationship 



N3. 1868, VOL. 72] 



to producers as to consumers, yet, while such publications 

 may be supposed to benefit the latter class uniformly, a 

 considerable injustice might conceivably be done to one of 

 the former the ware of which took a lower place in the 

 scale. This danger is exemplified to some e.xtent in the 

 Iowa report, which mentions the names of firms in con- 

 junction with the results, and the effect is too much like 

 an advertisement. New Jersey adopts the plan of publish- 

 ing the laboratory number of the test ; the manufacturer 

 has the result communicated to him privately. For our 

 part we doubt the wisdom of such publication, except upon 

 lines similar to those on which watches and thermometers 

 are tested in this country. 



But good maps of the distribution of the clays, the 

 preparation and collection of comparable data of the 

 physical and chemical properties of the raw materials, 

 experiments on the results of blending hitherto unworked 

 clays with one another and with known clays, and the 

 coordination of the information and samples in a manner 

 accessible to all, is the legitimate duty of a State depart- 

 ment, and of the utmost value to all sections of the 

 community. 



The Geological Surveys of Iowa and New Jersey have 

 performed most of these duties in a manner which cannot 

 fail to be appreciated. When we remember that in addition 

 to this Geological Survey work there is in each State a 

 well equipped ceramic laboratory for testing and for in- 

 struction in the manufacture of all grades of wares — the 

 department of ceramics in the State College of New Bruns- 

 wick has an outfit in the brick-making section capable of 

 turning out 20,000 bricks per day — we are constrained to 

 turn our eyes to our own State, where we see the capital 

 pioneer effort of an individual, George Maw, nearly fifty 

 years ago — and what beside? "Comparisons," as Mrs. 

 Malaprop says, are "obvious." 



THE CEREBELLUM: ITS RELATION TO 

 SPATLiL ORIEXTATJON AXD LOCO- 

 MOTIONS 



AS the cerebellum is well represented in the lowest 

 vertebrates and undergoes relatively little change in 

 form with the higher development of the rest of the brain, 

 it must be regarded as a fundamental structure of the 

 vertebrate nervous system. This may be one of the reasons 

 that much interest has centred in its study and in the 

 attempt to define its functions in exact physiological 

 terms. Though Willis (Oxford, 1660) noted the intimate 

 connection between the cerebellum and pons Varolii, and 

 recognised that the trapezial fibres of the latter are a 

 cerebellar and not a cerebral system, and though Majendie 

 laid the first foundations of our knowledge of its func- 

 tions, it has only been of recent years that we have gained, 

 chiefly from the work of Luciani and the workers who 

 followed him, satisfactory insight into its anatomy and 

 physiology. 



In the lecture. Sir Victor Horsley analysed the con- 

 clusions on its functions which have been obtained by 

 the destruction and stimulation methods of study, and in 

 addition contributed from his clinical and laboratory ex- 

 perience some facts which help to elucidate the rile it 

 plays in our nervous economw 



In the first place all recent work confirms the con- 

 clusion formulated years ago by Edingcr, that the cere- 

 bellum is essentially an organ for the reception of certain 

 sensory impulses. Systems of fibres ascending from the 

 spinal cord convey to it part of the sensory impulses which 

 enter through the dorsal roots from the cutaneous and 

 more deeply placed peripheral nerves. These tracts of 

 fibres end in the cerebellum exclusively in its vermis or 

 middle lobe. To the vermis also come direct root fibres 

 of the vestibular nerves which collect from the semi-circular 

 canals, the organs of the special sense of orientation in 

 space, the sensations of change of position and of the 

 position of the head in space. The lateral lobes of the 

 cerebellum, on the other hand, are in connection through 

 the pontine grey mat'ter with the temporal lobes and with 

 the kiuEesthetic cortex of the forebrain. All these systems 

 which conduct to the cerebellum end in its cortex, and 



1 Abstract of Boyle Lecture delivered bv Sir Vicrrr Horsley, F.R.S., 

 be ore the Junior Scientific Club of the Univeriity of Oxford, June 5. 



