i6 



SCIENCE 



[Vol. XXII. No. 545 



thickets of brush wood. He remains with us until late in the 

 Spring, indeed the other wrens have young ones before he thinks 

 ■of leaving for his northern -'summering place." Last year 1 saw 

 some on the 33nd of April. I sent one of them to Washington 

 ■wliere the "bird doctors" pronounced it "aztecus."' 



5 Salpinctes obsolelus. Rock Wren. 



This bird hardly deserves a place to itself, being quite uncom- 

 mon and differing little in appearance and mode of life from 

 tlie Canon wren, which seems to represent it with us. It is more 

 common further west. Indeed, this is the most easterly record 

 in Texas of its occurreuce. 



METALLIC CARBIDES. 



BY F. P. VENABLE, CBAPLE HILL, N. 0. 



Ttns name is given to compounds formed by the direct union of 

 carbon with the metals. They are not numerous nor do they 

 seem to be easy of formation and it is very difficult to prepare 

 them in a pure and definite form. Consequently they have been 

 but little studied so far. None of them are known to occur in 

 minerals of terres-trial origin. 



Interest in these bodies has been heightened of late by the 

 discovery of new ones, and by the instructive decompositions of 

 some of them. 



First as to the general mode of formation. They are usually 

 formed by the action of intense heat upon the metal in the 

 presence of carbon. The form of this carbon is capable of 

 being greatly varied. Graphite, amorphous carbon and many 

 hydrocarbons can be used. The carbide is especially formed 

 when the metal is being extracted from its compounds, that is, in 

 the nascent state. Several metals thus unite with carbon in 

 the process of manufacture, as zinc, copper and notably iron, 

 and the presence of thecarbidesrenders the metal hard and brittle. 

 The purification and analysis of these bodies is not at all an easy 

 problem, and hence little or nothing is known of their formulas 

 or chemical constitution Five or more formulas have been 

 assigned to iron carbide, and, of course, several may exist, still 

 the correctness of any of these formulas is questionable. 



The heat of the ordinary furnace is sufficient to form the 

 carbides of the metals already mentioned. For others, more 

 recently discovered, as the carbides of aluminium, of calcium, 

 of barium, etc., the intense heat of the electric furnace is neces- 

 sary. The first of these, aluminium carbide, is a most interesting 

 body, of a light golden yellow color, it can be gotten from the 

 electric furnace in a mass of corundum and metallic aluminium. 

 It was described first by Sterry Hunt. Though it will stand 

 intense heat in the air without appreciable change, yet really it 

 is undergoing change all the time as is proved by the odor of 

 hydrocarbons coming from it and the fact that left to itself in 

 air it crumbles in a few weeks into a mass of white alumina. A 

 few shining golden scales of the pure substance can be separated, 

 but so far no analysis has been given to the world. 



All of these carbides, under certain conditions, give ofif their 

 •carbon in the form of hydrocarbons. The same smell can be 

 detected in all during their decompo.«ition. In some cases, as 

 iron and zinc, the decomposition is caused by the action of an 

 acid. The carbides of the earths decompose in moist air and 

 more rapidly in water. Calcium carbide decomposes the most 

 energetically of them all. The evolution of the hydrocarbons 

 would be called violent. Of course, the hydrogen needed for the 

 reaction comes from the decomposition of the water or from the 

 liydrogen acid. 



A most interesting fact recently published in the scientific 

 journals, is that the calcium carbide on decomposition yields lime 

 and pure acetylen gas. The acetylen seems very pure. A 

 thousand cu. cm. of the evolved gas was passed into an 

 ammoniacal solution of copper chloride and not a bubble went 

 through. All was absorbed and precipitated. This is very im- 

 portant becaase the modes of preparing acetjlen in common use 

 are tedious or expensive, and hence this important hydrocarbon 

 has not been as carefully studied as it otherwise might have been. 



The formation of hydrocarbons by the decomposition of iron 

 carbide has furnished a basis for one of the theories as to the origin 



of petroleum. If great quantities of iron carbide existed beneath 

 the earth's surface and were subjected to decomposing influence;, 

 such oils and gases as are found in petroleum regions might very 

 easily be formed. 



So far there has been little utilization of these carbides commer- 

 cially. One of the purer forms of iron carbide is used in a 

 prucess for preparing metallic ssodmm, and the iron carbide in 

 cast iron confers upon it many of its useful propeities. If these 

 bodies can bp produced cheaply enough, however, there is strong 

 probability that certain of them will prove very useful. 



PHILOSOPHY IN THE COLLEGE CURRICULUSl. 



BY HOLMES DYSINGER, CARTHAGE COLLEGE, CARTHAGE, ILL. 



Studies under the name of philosophy are to be found in 

 almost every college curriculum. Either because the subject is 

 too vague or abstruse for the comprehension of the average stu- 

 dent, little more than elementary jsychology, which is rightly 

 regarded as a necessary part to the introduction to the subject 

 proper, and a brief discussion of practical ethics, are taught in most 

 of the schools outside of the few real universities. While the 

 number of subjects advocated for introduction into the college 

 course is increasing constantly, one so fundamental as philosophy 

 should not be neglected. Apart from its theoretical value, it has 

 practical bearings upon the intellectual range of a man, regardless 

 of the system he adopts, that commend it to the thoughtful con- 

 sideration of educators. 



The subject-matter with which philosophy deals bears a peculiar 

 relation to all other subjects in the course, in as much as its office 

 is, partly at least, to systematize and explain all the principles of 

 the particular sciences. This gives the unity so desirable in a 

 course of study, and so essential to the thoroughly-trained mind. 

 From this it serves the highest purpose in education and deserves 

 a prominent place in every course of liberal cultare. 



The philosophical povters of man are last in order of develop- 

 ment. The subject-matter makes it necessarily so. It is the 

 most abstruse of all forms of knowledge. The mind in its unfold- 

 ing passes up thmugh perception and conception to the realm of 

 widest generalizations and the discovery of the principles that are 

 assumed in all our thinking. Philosophy deals with forms of 

 knowledge that stand at the farthest remove from that furnished 

 in so-called presentation — the first development in the mind's 

 unfolding. 



When the mind reaches that stage of development in which it 

 apprehends the principles fundamental to all knowledge, it turns 

 in upon itself and critically examines its own processes and as- 

 sumptions to determine the certainty of being and the validity of 

 our knowledge. This is the highest stage in man's intellectual 

 ascent. Here he stops. He has completed the circuit of the 

 globe of knowledge. He started with the facts furnishei in sense 

 and consciousness, and ends in the principles that underlie and 

 embrace all knowledge. These stand accredited in his own think- 

 ing. Beyond this the mind of man cannot penetrate. 



That many students cannot attain this stage of knowledge is 

 evident to all who have taught the upper classes in our colleges ; 

 that but few who attempt it get further than the outer court, is . 

 to be expected ; but that all are gr^ ally benefitted intellectually 

 would not be denied by those who have looked into the merits of 

 the case and examined the evidence with impartiality. A few 

 additional facts will give our reasons for this conclusion. 



Notwithstanding its abstruseness, as a discipline in thinking 

 and in logical method, philosophy has no equal. Facts as fur- 

 nished by the senses and distinguished from principles are not 

 dealt with in philosophy, but the relation of facts to one another 

 and to all things else. All these in a sjstem of philosophy de- 

 serving of study or worth elaboration must be included in their 

 relations of coordination and subordination. The unity of all 

 b ing is the ultimate problem of philosophy. A nairower range 

 and lower ideal may sati.'^fy science, but it cannot attain to that 

 which comprehends all knowledge. Only the mind well disci- y 

 plined in logical method can grasp the facts, but the one who •* 

 attempts to do so will develop a power that is the possession of 

 few and the desire of all 



