A VALUABLE OFFER 



" SCIENCE" has on hand a few sets of bound volumes which the 

 publisher has decided to offer to subscribers — either new ones or renewals — 

 for the coming month at the following tempting rates : 



OFFER NUMBER ONE. 



We will give to any one sending us, in advance, seven dollars and a half, 

 one years subscription to SCIENCE and two back volumes handsomely 

 bound in cloth. 



OFFER NUMBER TWO. 



For ten dollars we will give a year's subscription and four back volumes 

 bound in cloth as above. 



Subscribers whose term expires later than July i may avail themselves 

 of this offer by sending in their renewals with the money before July ist. 

 Our offer will not remain open after that date. One dollar must be added 

 to either of the above offers in the case of foreign subscription. Address 



" SCIENCE," 47 LAFAYETTE PLACE, NEW YORK. 



IMPORTANT TO SUBSCRIBERS. 



The friends of SCIENCE can render valuable aid to the journal by 

 recommending it to possible new subscribers. Recognizing that such assist- 

 ance is of real value to us, we will, at any time, extend for six months the 

 term of a subcriber who sends us, with the money for one years subscrip- 

 tion, a name not already on our list. 



Subscription price, $5.00 a year. To foreign countries, $6.00. Address 



SCIENCE, 47 Lafayette Place, New York. 



