cxxxiv GENERAL SUMMARY OF SCIENTIFIC AND 



west portion of New Guinea are copper-colored, about five 

 feet three inches in height, and with good features. The 

 hair of the men is worn frizzled out in a large mat, and or- 

 namented with feathers; that of the women is always cut 

 short. Both sexes go almost naked. Their weapons are 

 wooden spears and swords, clubs, slings, and stone V-shaped 

 hatchets ; but no bows and arrows are seen anions: them. 



Human jaw and spinal bones are worn as bracelets and 

 ornaments, and the wearers appeared to wish to have it un- 

 derstood that they had eaten the original owners of the bones. 

 The houses are built, after Malay fashion, on poles raised five 

 or six feet from the ground, and consist of one large apart- 

 ment, w r ith peaked gable ends and a saddle roof. Dogs, cats, 

 and pigs are kept ; also tame cassowaries, birds, and a small 

 species of opossum bear. 



Their fishing -nets are similar to an English seine, with 

 shell sinkers and light wood floats, and are from one to twen- 

 ty fathoms in length. The material is made by the women, 

 from the fibre of a small, nettle-like plant, and possesses the 

 strength of ordinary seining twine. 



MICROSCOPY. 



I. MICROSCOPIC APPARATUS AND OBJECTIVES. 



In a paper upon microscopic spectrum apparatus, by Mr. 

 H. C. Sorby, and published in the Monthly Microscopical 

 Journal, May, 1875, he proposes for the future to adopt the 

 plan of expressing the position of the absorption bands in 

 terms of wave-lengths, instead of referring to an arbitrary 

 scale. He states that probably it is a true general law that 

 when the spectrum of a substance contains a number of 

 well-marked absorption bands, they are related to one an- 

 other in a perfectly definite manner, and a far more uniform 

 connection exists between the wave-length of their centres 

 than between any other condition. When the relation be- 

 tween the bands in different closely connected compounds is 

 observed by the wave-length method, a relation is recog- 

 nized which would not be possible if any arbitrary scale w r ere 

 adopted, and this not only when the physical state is the 

 same, but when the substance itself is chemically modified. 

 In view of this relation between the spectra of compounds 

 known to be related in a simple manner, and which can be 



