Apbil 30, 1920] 



SCIENCE 



437 



suggested is ever followed or not, it is at 

 least fairly clear that the Tise of symbols in 

 the various special and restricted subjects can 

 be regulated with far less perplexity and con- 

 flict than attends the attempt to provide a 

 single system to fit the whole of a very com- 

 plex science. Another important conclusion 

 is that voluntary effort and cooperation can 

 accomplish much, even without any formal 

 committee. For instance, most of the exist- 

 ing diversities in symbols are due to inad- 

 vertence or negligence, not to real difference 

 in opinion or taste. Most of them would 

 have been avoided if writers had simply made 

 it a rule to notice the symbols of their pre- 

 decessors, and not make changes without any 

 reason. There is little doubt that the major- 

 ity of writers are willing to follow this rule 

 as soon as their attention is directed to it. 

 Where previous usage differs, or where some 

 writer wishes to make changes for a reason, 

 the individual writer's judgment may not be 

 wise. In such cases cooperation, through cor- 

 respondence or otherwise, between different 

 writers is advantageous. Such cooperating 

 writers, however, will usually desire the co- 

 operation of a formal committee. Indeed, 

 my own reason for venturing to present 

 these suggestions to the public is that I 

 happen to belong to a small group who are 

 willing to make mutual concessions and so 

 secure a uniform set of symbols in a new 

 minor subject, and who wish to have their 

 work in this direction given the improvement 

 and greater promise of permanence that would 

 come by having it passed upon by a recog- 

 nized committee. 



The symbols used in diagrams, and in 

 many cases the forms of the diagrams them- 

 selves, can also gain by standardization. Cer- 

 tain familiar conventions have long been used 

 in electrical diagrams, but in general the field 

 is so divided and varied that here, even more 

 than with the symbols used in equations, 

 piecemeal and detailed standardizations seem 

 at once easiest and most useful. Sweeping 

 and absolute rules are almost sure to prove 

 detrimental in some cases, and have aroused 

 opposition. Even in striving for uniformity 



the greatest uniformity is not necessarily al- 

 ways the greatest benefit. Moreover, a set of 

 general rules, formulated once for all, does 

 very little to unify the special and minor 

 details, which are, if anything, the most im- 

 portant, since they are the most numerous, 

 and hardest for the reader to remember. The 

 value of general rules for symbols and dia- 

 grams will hardly be denied, but a large 

 measure of attention to separate subjects 

 seems likely at once to be of value in itself 

 and to avoid much of the difi&culty and con- 

 flict which have hitherto impeded progress in 

 standardization of symbols by more wholesale 

 methods. 



Walter P. White 

 Caenegie Geophysical Laboratory 



carbon monoxide 

 To THE Editor of Science : One of the char- 

 acteristic by-products of our industrialism is 

 carbon monoxide and the mild hysteria which 

 one finds in certain parts concerning the pos- 

 sible accumulation of this compound in our 

 atmosphere is interesting as an example of a 

 little learning. The report of the press that a 

 high percentage of this gas was discovered in 

 some of our camps where automobiles, aero- 

 engines and gas engines in general were ope- 

 rating has given color to the fears expressed 

 by some of our scientists who should know 

 better. There is prob.ably more carbon mon- 

 oxide produced during a severe lightning storm 

 in a given locality than is emitted by our coke 

 burners, gas engines and other sources in in- 

 dustry during much longer periods. The si- 

 lent discharge which proceeds during storms in 

 mountainous areas produces much of the gas. 

 Now while carbon monoxide is inert chemically 

 and scarcely absorbable by ordinary laboratory 

 methods, under natural conditions there are 

 sources of disposal which guarantee that the 

 gas does not accumulate rapidly, at least, in 

 our atmosphere. Chlorophyll " fixes " cart>on 

 monoxide in a stable way, so that much 

 chlorophyll is lost to plants in regions where 

 there is an unusually high concentration of the 

 gas, being rendered impotent in photosynthesis 

 by the attachment of CO. In like manner, 



