List of the Plants of Chile. 299 



A comparison of the third series with the two preceding, will 

 show that at the comparable temperature, cast iron is capable of gen- 

 erating more steam for each unit of weight in the metal, than wrought 

 iron. It may possibly be found that the temperature of luminousness 

 in the two kinds, is different. But from heating similar masses of 

 the two, side by side, in the same exposure, and observing no differ- 

 ence in the time of coming to redness, I have been led to attribute 

 the difference to a difference in the specific caloric of cast and 

 wrought iron; a circumstance which would probably be sufficiently 

 accounted for, by the difference in their constituent elements. 



The mean amount of cast iron to each pound of steam in the nine 

 experiments marked comparable, is 8//^'^ ^^s. We might probably 

 assume 8J as the number, without material error. 



A great many experiments, tending to show the period of most 

 rapid action of hot metal upon water have been performed, but the 

 limits of the present paper require that the results of these, as well as 

 the account of experiments on copper, brass, silver and gold, should 

 be postponed to a future number. 



Art. VIII. — List of the Plants of Chile; translated from the '^Mer- 

 curio Chileno," by W. S. W. Ruschenberger, M. D. U. S. Navy, 



(Continued from page 70.) 



Ammi Visnaga. Lamark. Vulgarly Visnaga; very common in 

 fields. It is a poor plant, of which no use is made, except that 

 tooth-picks are formed of its dried peduncles. It is not eaten by 

 animals and it would be useful to find the means of extirpating it 

 entirely. 



Amygdalus communis. Linn. Almond. A cultivated tree, which 

 it would be proper to multiply. On account of its qualities, and the 

 different uses to which the almond may be applied, its extensive cul- 

 tivation would, in a commercial view, be advantageous to the country. 

 Its wood serves for the finest kinds of joiners' work. The oil of al- 

 monds, so useful in medicine, is, when found at all, always very ex- 

 pensive in this country. The variety with a soft shell is to be prefer- 

 red, on account of the facility with which it is broken. The Amyg- 

 dalus Persica, Linn, is among the most common fruit trees. A great 

 number of varieties, early and late, are enumerated, both with naked 



