474 EXPERIMENT STATION RECORD. 



20 (ISUG), No. 88, Repert., p. 25S ).—Aa the result of experiments in this direction the 

 author has settled upon the following solution as the best: Formalin 750 cc., dis- 

 tilled water 1,000 cc, kaUum nilricum 10 cc, and kalimn aceticiim 30 cc. Generally 24 

 hours' treatment in this solution is said to he sufficient. The specimens are then 

 drained and placed in 80 per cent alcohol. They are usually kept finally in a mix- 

 ture of equal parts of water and glycerin and 30 parts of potassium acetate. 



General principles of zoology, R. Hektwig, translated by G. W. Field (iVew 

 York: Henry Holt if- Co., 1806, pp. 220, fins. 110).—T'h\s volume is a translation of the 

 first part of Hortwig's " Lehrbuch der Zoologie," and treats of general zoology. The 

 history and development of the various branches of zoology are given at considerable 

 length, and also the bearing of zoology upon various theories of evolution. General 

 anatomy, embryology, the relation of animals to each other and to plants, and geo- 

 graphical distribution are each treated iu considerable detail. The broad general- 

 izations of the author can not fail to interest those who are not already acquainted 

 with them from the original. 



METEOROLOGY. 



On periodicity of good and bad seasons,' H. C. Eussell {Nature, 



54 {1S96), No. 1399, pp. 379, 380). — The dates of recorded droughts, i. e., 

 "periods of months or years when little rain falls,'' have been collected 

 with a view to determining the period of their recurrence. It is first 

 shown that during the 108 years since the foundation of the colony of 

 New South Wales "the most pronounced droughts recur with great reg- 

 ularity; that is, at every 19 years." This period was also found to hold 

 for Indian droughts. 



"Another set of dry periods, more intense and relatively shorter than 

 the first series, was found also to recur at intervals of 19 years. One 

 of these droughts falls regularly between a pair of the more extensive 

 droughts previously referred to. 



"History says very little about droughts prior to A. D. 900." It 

 records droughts on 44 of the 52 dates indicated in 19-year periods 

 between that year and the present time, and 6 of the 8 missing droughts 

 o(;cur between 900 and 1000, an interval when history was very incom- 

 plete. 



"Records of 20 B. C. droughts were found, all of which, with one 

 exception, fit into our 19-year cycle. The intervals between them are 

 multiples of 19 years. . . . 



It appears that "this law of climate was well known to the Jews, the 

 Egyptians, and other ancient peoples; they at least knew how to fore- 

 cast droughts successfully." 



The author considers the moon the prime motor in this periodic occur- 

 rence of droughts. Investigations on this subject are still unfinished, 

 but the results thus far obtained indicate that — 



"When the eclipses congregate about the equinoxes — that is, iu March and Septem- 

 ber — they do so iu the years which give us great droughts. Further, that when the 

 eclipses accumulate in February and March, that is, at the vernal equinox and the 

 month before it, and September, the autumnal equinox, and the month before it, 



' Read before the Royal Society of New South Wales, June 3, 1896. 



