December 6, 1894J 



NATURE 



141 



As we have seen, most of our forest trees are of a social 

 l.aracter. With few exceptions, they keep company with 

 her kinds than their own ; they appear in mixed forests. 

 Hence, where certain specie-;, as the pines and spruces, become 

 gregarious, and form unmixed, pure forests, the axe of the 

 lumberer does not as a rule level the entire forest, but he selects 

 the kinds which he wishes to use — he culls the forest. At first 

 sight this would appear rather an advantage for the existence of 

 the forest. So it is from a botanic, geographic, or landscape 

 point of view, yet from an economic point it is exactly the 

 reverse — it is disastrous. 



In the well managed forests of Germany the undeserving 

 ^pecies are exterminated, and the most useful fostered, just as 

 'he agriculturist exterminates the weeds and cultivates the crop. 

 Not only is the forest there confined to those soils and locations 

 Aliich cannot be used to better advantage, or which require a 

 ) irest cover in order to protect the soil against detrimental dis- 

 placement, but it is so managed as to become a more and more 

 valuable resource, a crop of increasing importance, under the 

 management of skilled foresters, of whom, in a late debate on 

 the floor of the Landtag of Prussia, it was said that "While 

 most other productive business has declined, the forest ad- 

 ministration has steadily improved and yielded increasing 

 revenues." 



The battle of the forest in this country is now fought by man, 



lie unintelligent and greedy carrying on a war of extermination, 



. ithout the knowledge that victory may lead eventually to iheir 



.vn destitution; the intelligent and provident trying I-- defend 



le forest cover, and endeavouring to prevent its removal from 



;ch lands as cannot serve a better purpose, and to restrict the 



lie of the balance to such rational harvest of its material, with- 



at injurious effects on soil and water conditions, as will insure 



:i ever reproducing crop and a permanent national resource. 



While man may study the geography of the earth as it exists, 



jre is about the only opportunity for him to make geography, 



J shape the surface conditions of the earth, and even to some 



extent influence its climatic conditions. 



The lecturer then referred to the Adirondacks in particular, 

 showing views of forest destruction by fire, water storage, and 

 lumbering, and claiming that they need especially conservative 

 : L-alment, because the soil itself theire is made by the forest, the 

 ;tT covering the native rock formed at the rate of one foot 

 n 300 to 500 years by the decay of foliage and litter, and hence 

 ts loss by washing of the rains is practically irremediable. 



lie showed the paramount interest which the State has in 



maintaining favourable forest conditions, and claimed that the 



rivaie owners, being naturally interested mostly in the timber 



Illy, and not caring for the future generations or distant and 



: lirect benefits to others, could not be expected to manage 



- nservalively. 



Let it not be overlooked, that the State is not only the 



representative of communal interests as against individual 



iteresls, but also of future interest as against the present ; the 



I ivate interest is not sufficient to protect this class of lands; 



•hat State ownership or, what is more objectionable and less 



ettective. State supervision of private forest lands is indispens- 



Me in those regions where the forest subserves other functions 



I ui that of mere material supply. 



Grant for once that the community is interested in the pre- 



crvation of the forest cover and its rational use with proper 



reijard to the maintenance of permanently beneficial conditions, 



'i.it the community would suffer from a destructive policy in 



lose watersheds, and you must come to the logical conclusion 



. t the community alone can be expected to guard its interests, 



lit the community, the State, must own and manage these 



. ' lods. 



This does not mean that the same should be kept in virgin 



ndition and unused, that the timber should be left to rot, and 



•J productive capacity of nature's forces be allowed to go to 



iste, but that a conservative management be instituted, keep- 



il; in view both the indirect and the direct benefits of the 



rest cover, utilising the crop without detriment to the forest 



jnditions. 



This, to be sure, is not done by such rules of thumb as a 



restriction to cutting trees of given diameter, nor can the legis- 



i.itor prescribe to the forest how to grow. He cannot be 



expected to legislate how many trees to cut, how many to 



leave, or to lay down rules of technical forest management, any 



more than he would attempt to prescribe the size of the pillars 



-upporting the roof of the Capitol, or to legislate on the pro- 



NO. 1310, VOL, 51] 



portions of an arch. It requires the knowledge, the experience, 

 the skill of a professional, technically educated engineer, just 

 as an eflective manageinent of the forest requires the knowledge, 

 the experience, the skill of professional foresters, and may not 

 be left to the ignorance and carelessness of the wood-chopper. 



May the wisdom of the people of New York, of their legis- 

 lators and executive officers, be equal to the difficuhies of 

 solving the problem as a business proposition, and settling it in a 

 common sense, business-like manner. May their intelligence 

 and business capacity at least equal that of other States and 

 nations, and forestall the disastrous consequences that follow 

 unavoidably from neutrality or improper partisanship in this 

 battle of the forest. 



yi 



THE RELATION OF ENERGY OF COMBINA- 

 TION TO ELECTRICAL ENERGY. 



HE problem of directly converting the storedup energy of 

 coal into available electrical energy is one of great import- 

 ance ; and as a first attempt to perform this operation, the ex- 

 periments made by Dr. W. Borchers, of Duisburg, and which 

 he described before the first annual meeting of the Deutsche 

 Elektrochemische Gesellschaft, possess great interest. The 

 author in the first place produced an electric current by the 

 ' ' combustion " of carbonic oxide gas. The original form of the 

 apparatus used consisted of a glass vessel divided into three 

 compartments by two glass plates which nearly reached to the 

 bottom of the vessel. In the two exterior compartments copper 

 tubes were placed, which served for the introduction of the car- 

 bonic oxide, while the middle compartment contained a bell- 

 shaped mass of carbon. This carbon bell constituted one plate 

 of the cell, and the oxygen was introduced by means of a tube 

 within this bell. As electrolyte the author uses an ammoniacal 

 or acid solution of cuprous chloride ; this liquid readily absorbs 

 both oxygen and carbonic oxide, and is therefore particularly well 

 suited to form the electrolyte in a gas battery in which these 

 gases are used. Coal gas which contains 5 per cent, of car- 

 bonic oxide was, alter the first experiments, used in place of 

 pure carbonic oxide. The copper tubes were weighed before 

 and after each experiment, and no decrease in their weight was 

 ever found. With such a cell working through an external 

 resistance of 01 ohm a current of o'5 ampere was obtained, 

 while with an external resistance of 50 ohms the difference of 

 potential between the terminals was o'4 volt. 



With a cell in which the outer compartments were filled with 

 copper turnings, in order to increase the absorption of carbonic 

 oxide by exposing a greater surface, and by ujing coal gas in 

 place of pure carbonic oxide, a maximum current of o'64 am- 

 pere was obtained, and by increasing the external resistance a 

 maximum difference of potential of o'56 volt was maintained. 

 The E.M.F. obtained by calculation from the heat developed 

 in the combination of CO and O is f47 volts, so that in the 

 above experiment 27 per cent, of the energy of combination of 

 the fuel is converted into electrical energy. Since a solution 

 of cuprous chloride dissolves hydrocarbons, powdered coal was 

 tried in place of carbonic oxide, when a maximum current of 

 o'4 ampere and a maximum E.M.F. of o'3 volt were obtained. 

 The above E.M.F. (O'J) corresponds to about 15 per cent, of 

 the energy corre-ponding to the oxidation of carbon. In the 

 case of the coal-dust, even when the liquid was kept in motion, 

 there was always a considerable falling ofTin the current, while 

 the pollution of the electrolyte by the coal would quite prevent 

 its use. With the gases, however, there is no falHng oflfof the 

 E.M.F., and this pollution of the electrolyte does not occur. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



C.\Mi;R1dge. — Dr. R. D. Roberts has been appointed chief 

 secretary for the University Extension scheme, in the room of 

 Mr. A. Berry, who retires at the beginning of the Lent Term 

 1S95. 



The General Board of Studies report in favour of steps being 

 taken to establish a closer connection between .\ddtncirooke's 

 Hospital' and the University teachers in the departments of 

 medicine, surgery, and therapeutics. 



The Syndics for State Medicine report that in the past year 

 fifty-six candidates presented themselves for examination in this 



