56 Proceedings of the American Philosophical Society. 



The laws which govern the other grades of this defect, Dr. Hays re- 

 marked, remain to be determined. 



There are certain persons who can accurately recognize yellow and 

 blue, and some who can recognize red, who cannot distinguish green ; 

 but whether or not there are individuals who can recognize the three 

 primitive colors accurately, and are yet unable to distinguish the second- 

 ary colors, must be left, Dr. Hays remarked, to further observation to de- 

 termine. 



It also remains to be ascertained, whether any person, having an im- 

 perfect perception of yellow, can recognize blue ; or with an imperfect 

 perception of yellow and blue, or of the latter alone, can distinguish red. 



Sept. 18. — A letter from Dr. John Locke, of Cincinnati, stated the re- 

 sults of two series of observations, each made with three horizontal nee- 

 dles, and concludes from the mean of them, that the relative horizontal 

 intensities at Louisville and Cincinnati, are as 1 to 0.9727. The dates of 

 the observations were March 7th, 10th, 11th, and 14th, 1840, at about 

 noon of each day. The correction for temperature, in each of the three 

 needles used, was obtained by experiments which are fully described, and 

 which gave the following coefficients : — for needle No. 1, 0.000125; for 

 No. 2, 0.000145 ; No. 3, 0.000058. 



The magnetic dip at Cincinnati, as determined by two series of obser- 

 vations, each with two needles, in March, 1840, was 70'^ 25'.5, and by 

 one series, in April, 70° 28'.8, and the dip at Louisville, by three series, at 

 nearly the same date, in March, 69° 54'.9. 



The relative total intensities thus deduced for a period corresponding 

 to March 10th, 1840, are, — Cincinnati, 1.000 ; Louisville, 1.003. 



Oct. 2. — The Committee, consisting of Dr. Horner and Dr. Hays, ap- 

 pointed on the 3d of January last, to report to the Society a description 

 of a donation of Mastodon Bones, made to the Society by a subscription 

 of members, gave in their report, which was directed to be printed in the 

 Transactions of the Society. 



The Committee, consisting of Dr. Hays, Mr. Peale, and Dr. Dunglison, 

 to whom was referred a paper entitled "Note of the Remains of the Mas- 

 todon, and some other extinct animals, collected together in St. Louis, 

 Missouri; by W. E. Horner, M. D., Professor of Anatomy, University of 

 Pennsylvania," recommended that an abstract of the same should be in- 

 serted in the Bulletin of the Society's Proceedings ; and on motion, the 

 report was accepted, and the committee discharged. 



The collection referred to, was made by Mr. Albert Koch — a German 

 resident in St. Louis, for the last five years — and has been obtained prin- 

 cipally from two localities, Rock Creek, twenty miles south of St. Louis, 

 and Gasconade County, two hundred miles above the mouth of the Mis- 

 souri river. It consists of two hundred or more teeth of the mastodon 

 and of the American elephant, a dozen or more lower jaws of the 



