346 ANNUAL OF SCIENTIFIC DISCOVERT. 



This experiment was repeated the following year, and when the potatoes 

 were about half grown a protracted drought commenced, and the crop did 

 not attain full size ; but so far as could be determined by observation, 

 quite similar results were clearly indicated. 



In the foregoing estimation of net results, I have not taken account of 

 the cost of culture and marketing, so as to show the actual profit of the 

 rop, because the cost and product differ so greatly in different sections of 

 the country. 



SUBSTITUTE FOR GUTTA PERCHA. 



Dr. Riddel, of Madras, has recently found, in making experiments on the 

 muddar plant of India, that its milky juice, when dried, became tough 

 and hard like gutta pereha, and precisely analogous to it. It is charred by 

 sulphuric acid, converted into a yellow resinous substance by nitric acid, 

 and but little, or not at all, acted on by muriatic or acetic acid or alcohol. 

 Spirits of turpentine dissolve it into a viscid glue, which, when taken 

 between the thumb and finger, pressed together, and then separated, shows 

 numberless minute threads, all which results correspond with those of 

 gutta percha. The muddar also produces an excellent fibre, useful in 

 the place of herap and flax. An acre of land cultivated with it would 

 produce a large quantity of fibre and juice. 



ON TBE PRODUCTION OF MUSHROOMS. 



It is the received opinion among botanists that mushrooms have but one 

 sort of seed, and that in this regard Nature has been less kind to them 

 than to seaweeds, mosses, and other crytogams, which she has provided 

 with numerous means of propogation and yet these are the plants which 

 grow and are reproduced with proverbial rapidity. In examining them 

 more closely than his predecessors, M. Tulasne thinks he has discovered 

 that they are mistaken ; that mushrooms, like mosses, possess the faculty 

 of being propagated,, not only by filamental elements, but also by buds, and 

 that they have, like some seaweeds, spores, or seeds, of two kinds, one 

 being of a higher order than the other, and corresponding to a more perfect 

 mode of multiplying. Independently of all the^e reproductive organs, 

 M. Tulasne mentions others, the spermaties, which are distinguished from 

 the others by their extreme tenuity. Proceedings French Academy. 



COLORATION OF SEA WATER. 



At certain periods of the year the Red Sea justifies its name by the 

 coloration visible in its waters. M. Ehrenberg ascertained that it then 

 held in suspension prodigious quantities of colored microscopic plants 

 belonging to the seaweed family. From the moment this observation was 

 made, it was deemed that it gave the explanation of a great many accident- 



