February 11, 1887. J 



SCIE2^CE. 



135 



show that he has high authority for his inertia-force. 

 But that Newton's vis insita or vis inertiae is quite a 

 different thing from Hall's inertia-force, will be evi- 

 dent from the following quotations : " Haec " [vis 

 insita] " semper proportionalis est suo corpori, 

 neque differt quicquam ab inertia massae, nisi in 

 modo concipiendi " (Newton's Principia, comment on 

 def . Ill) ; and ' ' Inertia and inertia-force must be 

 carefully distinguished" (Hall's pami^hlet, p. 6). 

 Minchin's ' force of inertia ' is just D'Alembert's 

 ' effective force,' and is not a force at all, but simply 

 the name given to the product o f the mass of a parti- 

 cle into its acceleration. J. G. MacGeegoe. 

 Halifax, Jan. 31. 



An Ohio mound. 



In company with five young men from the public 

 school of this place, on Saturday, Oct. 10, 1886, I 

 assisted in the exploration of a mound, located in 

 the northern jDart of Van Buren township, Shelby 

 county, O., an accotint of which may be of interest 

 to antiquarians. 



Twenty-iive years ago the mound was ten feet 

 high, and twenty feet in diameter at its base. It was 

 opened at that time by a Mr. Bobinson, the owner of 

 the farm, and a neighbor, but nothing was discov- 

 ered by them beyond the fact that it contained a de- 

 posit of the fragments of bones, ashes, and red 

 earth. A more careful examination, however, made 

 by digging a trench four feet wide through it from 

 east to west, revealed the fact that it was not only a 

 place of deposit for dead bodies, but a place where 

 human bodies were consumed by fire. A large por- 

 tion of the interior of the mound is composed of 

 calcined bones. Many of these bones, since their 

 calcination, have been filled by carbonate of lime, 

 and are now as hard and heavy as stone. There 

 were, no doubt, a few copi^er implements or orna- 

 ments deposited with the bodies, as the bones are all 

 highly colored with the salts of that metal. A care- 

 ful examination, however, failed to discover speci- 

 mens of the metal. A quantity of mica, sufficient to 

 give the debris a glittering appearance, was found 

 diffused through the entire mass. Deposits of red 

 clay were found in different portions of the mound, 

 of a deeper red than the red color produced by the 

 action of fire. 



One curious feature of the contents of the mound 

 was the large number of balls found, varjdng from a 

 half -inch to two inches in diameter. They have all 

 been burned, and are of about the hardness of soft- 

 burned bricks. The only relics found were a few 

 small fragments of pottery and a green slate tablet 

 three inches long, pierced by a hole at one end. 



C. W. Williamson. 

 New Bremen, O., Feb. 3. 



A method of labelling museum specimens. 



The task of so labelling a collection of rocks, min- 

 erals, or similar objects, that their identity can in 

 none but the most extreme cases be lost, is no light 

 one. A common method now employed consists in 

 painting a small area upon the object, which serves 

 ■as a background upon which the serial number is 

 again painted in a different color. Although the re- 

 sults thus obtained are lasting, the method is too 

 laborious. Another common method consists in 

 writing the requisite data with pen or pencil upon a 



slip of paper, which is then gummed to the speci- 

 men. This is, however, worthy only of universal 

 condemnation . 



After several years' experience in dealing with rock 

 collections, I have adopted the plan given below, 

 which is but a modification of that first mentioned. 

 Its advantages are, ease and rapidity in application, 

 legibility, and durability of results. The method, 

 then, is briefly this : take common lead paint, of any 

 desired color, and mix with ordinary varnish and a 

 very little turpentine instead of oil. Apply with a 

 brush over an area sufficiently large to accommodate 

 the catalogue number, or whatever data it may be 

 desired to put upon it. This quickly dries, giving a 

 smooth, glossy surface. With very vesicular rocks, 

 as some of the recent lavas, it is often best to even 

 the surface by means of a little plaster-of -Paris, ap- 

 plied with a knife-point, before painting the stripe. 

 Then take tube paints, — I use Winsor & Newton's 

 lamp-black, — mix thin with turpentine, and with 

 this and a common steel pen write the number on 

 the surface prepared as above. If the paint is just 

 the right consistency, — and this can be learned only 

 by experience, — the numbers can be written almost 

 as rapidly as with a pencil on paper. Both paints 

 had best be mixed in watch-glasses, or some shallow 

 vessel that can be readily cleansed, as they are, of 

 course, useless after once having become hard and 

 gummy. 



On colorless crystals, such as quartz, the number 

 can, perhaps, be best written with a marking-dia- 

 mond. On smooth dressed specimens, as polished 

 marble, the numbers can be written with pen and 

 paint without the first stripe. On account, however, 

 of the great diversity in color and texture of materi- 

 als, I have found it best to adopt a uniform system 

 for all, — a light-blue base with figures in black. 

 Any other sufficiently contrasting colors will, of 

 course, do as well. Geoege P. Meeeill. 



U.S. nat. mus., Feb. 5. 



Fish parasites in Meleagrinae. 



The occurrence of parasites or commensals in the 

 pearl-oysters or mother-of-pearl shells has been 

 known for a long time. Several years ago (1874), 

 Professor Putnam of Cambridge described, in the 

 Proceedings of the Boston society of natural history, 

 Fierasfer dubius, a small fish common to both coasts 

 of Central America, which sometimes inhabits holo- 

 thurians on the Atlantic, and pearl-oysters on the 

 Pacific side ; and he referred to a specimen of the 

 pearl-oyster in the Museum of comparative zoology, 

 in which a Fierasfer is embedded in the nacreous 

 substance of the shell. 



In June last Dr. Gunther, at a meeting of the 

 Zoological society (London), exhibited a similar 

 specimen. 



About a year ago, while examining certain material 

 belonging to the Mexican geographical commission, 

 I detected probably the same species enclosed in 

 nacre in a jaearl-oyster valve from the Gulf of Cali- 

 fornia, and two, if not three, instances of another 

 species of fish, apparently an Oligocottus (in the 

 opinion of Dr. Bean), similarly enclosed. The oc- 

 currence of a crustacean, the pea-crab (Pinnotheres), 

 under the same conditions, in a pearl-oyster shell 

 from Australia, was made known to the Zoological 

 society last April by Dr. Woodward. The forthcom- 

 ing report of the national museum will contain a 



