INDEX. 369 



Spawn, different seasons for fish to deposit their spawn, v. 23. 



Spawning, peculiar preparation of the lamprey for spawning, 

 v. 94. 



Spears, the horns of the stag the third year, ii. 317. 



Spermaceti, the oil of the cachalot easily converted into that 

 concrete ; efficacy of spermaceti in medicine very small ; 

 candles made of it substituted for wax, and sold cheaper, 

 v. 54-. 



Spermaceti whale, the Cachalot, described, v. 52. 



Spiders, in South America and Africa, as large as sparrows, 

 i. 351. The spider, for several months together, subsists 

 upon a single meal, ii. 3. Chief of our native spiders not 

 venomous ; their description, and habitudes ; the Martinico 

 spider's body as large as a hen's egg ; manner of making 

 their webs ; Lister has distinguished the sexes of this ani- 

 mal ; their coupling ; their number of eggs ; their bag to de- 

 posit their eggs ; their parental care ; enemies to each other ; 

 experiment made by M. Reaumur to turn their labours to 

 the advantage of man ; gloves made from their webs ; found 

 it impracticable to rear them, v. 393. 



Spiders (water), inhabit the bottom, yet never wet, but en- 

 closed in a bubble of air, surrounding them on all sides, v. 

 4-05. 



Spinal marrow and the brain, the first parts seen begun in the 

 embryo, ii. 20. 



Spinous class of fishes already extended to four hundred sorts, 

 v. 114-. Gouan's system and arrangement of the various 

 sorts of spinous fishes, 115. Their general leading marks and 

 difference from others ; of those which live in the ocean, 

 the dorado the most voracious, 128. 



Spirits of wine flame with a candle, not with a spark, i. 74. 



Sponges, opinion of Count Marsigli about them ; that of 

 Rumph and Jussieu set in a clearer light by Mr Ellis, vi. 

 196. 



Spoonbill, descriptions of the European and American spoon- 

 bill ; its manner of life, iv. 326. 



Spouts (of water) at sea, common in the tropical seas, and 

 sometimes in our own ; description of one in the Mediter- 

 ranean, by Tournefort ; solutions offered for this phenome- 

 non ; broken by guns firing bars of iron at them, which 

 striking them, the water falls from them with a dreadful noise, 

 and no farther mischief; those called typhons, sometimes 

 seen at land, differ from those at sea described by mariners ; 

 description of that observed at Hatfield in Yorkshire, in 

 1687. Land-spouts sometimes drop in a column of water 

 at or.ce upon the earth, and produce an inundation ; they 

 appear in the calmest weather at sea ; facts still wanting to 

 form a rational theory of them, i. 331. 



Springs (of water), experience alone can determine the use- 

 VOL. VI. A a 



