POPULAR SCIEKCE MONTHLY. 



Fla., which runs only during about 

 three months in summer and is dry the 

 rest of the year, thousands of a large 

 colony of Lnio ohcaus may be found 

 just buried in the sandy banks or 

 among the flags and rushes of the bot- 

 tom, where there is very little moisture, 

 all in healthy condition. Mr. Simpson 

 has laid these mussels in the sun for 

 months without killing them. The 

 specimens which live in perennial watei 

 seem to die soon if removed from it. 



while those which inhabit streams or 

 ponds that often dry up will live a long 

 time out of water. Some species in 

 rocky streams live in the crevices of the 

 rocks. In the Big Vermilion River, in 

 La Salle County, Illinois, a swift, rocky 

 stream, the author has found living 

 mussels that had been so washed about 

 that nearly all the epidermis was de- 

 stroyed. The shells in such streams are 

 usually heavier than those in more 

 quiet water. 



MINOR PAEAGRAPHS. 



Prof. Frederick Starr, of the 

 University of Chicago, has made two ex- 

 cursions to Mexico for the purpose of es- 

 tablishing the physical types of the abo- 

 rigines by means of measurements, pho- 

 tographs, and casts. He studied twelve 

 tribes, half of which were almost un- 

 known to science, and made measure- 

 ments of more than eleven hundred and 

 fifty men and three hundred women. 

 On his last trip he rode one thousand 

 miles among the mountains on horse- 

 back. In a recent paper in the Open 

 Court he takes notice of frequent and 

 curious survivals of pagan belief to be 

 remarked among these peoples, although 

 they are all supposed to be devout Chris- 

 tians. In one instance, which is spe- 

 cially described, an idol bearing some 

 resemblance to those found among the 

 ruins of the ancient cities occupied a 

 station in the church by the side of the 

 crucifix, sharing the honors with the 

 statue of the Virgin on the other side. 

 Grief and consternation prevailed among 

 the Indians when the idol was taken 

 away by the ecclesiastical authorities. 



The question of the increase of in- 

 sanity in England during the last few 

 years is regarded as assuming a serious 

 aspect, and the report of the Commis- 

 sioners of Lunacy for 1898, showing the 

 largest annual increase yet recorded, 

 the Lancet says, reveals the gravity of 

 the situation. Other collateral facts 

 given in the report " add to the serious- 

 ness of the outlook." The increase in 

 the number of inmates in institutions 

 for lunatics is attended with a falling 

 off in the recovery rate, which is lower 

 for 1898 than that of the previous year, 

 and even than the average of the last 

 ten years. A steady diminution in the 

 recovery rate has appeared also during 



each period of five years since 1873. 

 The attempt to account for the increase 

 of lunatics in public and private asy- 

 lums by supposing that it is made up 

 by removals thither from workhouses or 

 from the care of relatives fails, for it is 

 shown that this class of insane is in- 

 creasing too, though slowly. The sub- 

 ject is regarded as of so much impor- 

 tance that it was considered and dis- 

 cussed in the Psychological Section of 

 the British Association at its Bristol 

 meeting in 1899. 



A process by which calcium car- 

 bide can be continuously produced more 

 cheaply than by the process at present 

 in use is reported, in Industries and 

 Iron, to have been discovered by Pro- 

 fessor Freeman, of Chicago. In the new 

 process a huge arc lamp inclosed in 

 brickwork in the interior of a furnace 

 is employed. The upper electrode of 

 the lamp is hollow, and through it is 

 fed a powder composed of common lime 

 and coke. This powder, being carried 

 through the upper carbon directly into 

 the electric flame, is melted by the in- 

 tense heat, and molten calcium carbide 

 runs away from the furnace. It is esti- 

 mated that the carbide is produced at a 

 cost of half a cent per pound. 



NOTES. 



A new method of securing more per- 

 fect combustion, described by Mr. Paul 

 J. Schlicht before the Franklin Insti- 

 tute, is based on the fact, described by 

 the inventor, that if a current of air is 

 properly introduced into a chimney flue 

 through which hot products of combus- 

 tion are escaping, it will flow in a direc- 

 tion contrary to theirs, and, becoming 

 heated in contact with them, will reach 



