972 



SCIENCE 



[N. S. Vol. XXIX. No. 755 



(most arbitrary limitation of all) to non-con- 

 dimental preservative3 not naturally present 

 in the food. 



In Fig. 2 are shown several possible forms 

 for the preservative curve, alternate to the 

 form given in Dr. Wiley's diagram. Two of 

 these, ADE and FGE, represent the preserva- 

 tive as beneficial in small quantities and in- 

 jurious in larger. The former represents the 

 preservative as essential in some quantity; in 

 other words, it would make the difference be- 

 tween food and preservative one of quantity 

 merely, not one of kind. A curve of this kind 

 is conceivable for a preservative such as ben- 

 zoic acid or salicylic acid, both of which are 

 normally present in minute quantities in many 

 fruits. 



The writer does not mean to assert that the 

 curves for any preservatives have been shovni 

 to have the forms represented in Fig. 2. What 

 he does wish to emphasize is that there is noth- 

 ing in the mathematics of the case requiring 

 them to have the form represented in Dr. 

 Wiley's diagram, and therefore no justification 

 for the argument that chemically preserved 

 foods are injurious because the preservatives 

 produce injurious effects when administered 

 in quantities larger than would be contained 

 in chemically preserved foods. 



J. F. Snell 



Macdonaib Coulege, 

 Quebec, Canada 



the chalk formations of northeast texas 

 In the American Journal of Science for 

 May, 1909, Article XXIX. is entitled "The 

 Chalk Formations of Northeast Texas," by 

 Mr. 0. H. Gordon, the substance of which is 

 to prove that the two formations of Texas, 

 originally defined by me as the Austin chalk 

 and the Anona chalk, are identical. 



If such is the case, and I have long believed 

 that it might be so, Mr. Gordon would do a 

 service to science in proving the fact. I think, 

 however, that in this paper where the author 

 has entered into the question of record, his 

 statements are neither complete nor accurate. 

 I spent many years of my life in endeavor- 

 ing to define the many Cretaceous formations 



of my state, and to disentangle them from 

 previous confusioiu The various contribu- 

 tions thereon were progressive, and after the 

 date of the last paper cited (1893) by Mr. 

 Gordon as coming from me and before I re- 

 tired from the subject, I learned and published 

 much. A final work was published in which 

 the previous results were summarized and 

 errors corrected. Furthermore, the uncer- 

 tainty as to the position of the Anona chalk 

 was clearly stated. It certainly would seem a 

 matter of justice for Mr. Gordon, in citing 

 my views, to cite the latest published ones. 



In the final work alluded to I clearly stated 

 on page 341 : 



That the writer has considered this chalk 

 (Anona) to represent a higher horizon than the 

 Austin chalk, but its exact relationship is a sub- 

 ject of future determination. 



Also on page 337 I note the difficulty " owing 

 to the lack of (continuous) outcropping sec- 

 tions " of separating the Austin chalk from 

 the Navarre formations in the Red Eiver 

 district. 



Furthermore, in discussing the correlation 

 south of Eed River of the various members of 

 the Upper Cretaceous in northeastern Texas, 

 I confessed my " utter inability, notwithstand- 

 ing the years of study, to correlate the various 

 outcrops of these beds, nor can it be done by 

 minute paleontologic research, such as he (the 

 author) has not had opportunity to under- 

 take," and such as Mr. Gordon confesses he 

 has not undertaken. 



Mr. Gordon does not even mention the paper 

 above quoted, which was my last work on the 

 Cretaceous and which is entitled " Geography 

 and Geology of the Black and Grand Prairies, 

 Texas, Twenty-first Annual Report of the 

 United States Geological Survey," Washing- 

 ton, D. C, 1902. 



So far as the writer is concerned, it is a 

 pleasure to see other workers continue the 

 researches in the geology of Texas, where 

 there are hundreds of problems and details still 

 unsolved and unrecorded, but I do thinJs 

 it fair that if an author endeavors to present 

 a record of previous researches, and opinions, 

 that they should be cited fairly. The score or 



