S12 



On an error in Dr. Thomson's Mineralogy. 



[April 



2 atoms of phosphoric acid. 



5 atoms of. water. 



Therefore RifFault's salt contained only half the water thatBrande's did. 



There are points, which if cleared up would be of the great- 

 est service to mineral analysis. How many there are in India, 

 who have ample leisure to devote to such pursuits, and the appara- 

 tus required is quite trifling, and might all be packed in a bullock 

 trunk. With all the activity of chemists in Europe, there is still a great 

 deal of work to be done ; there are many salts the composition of which 

 lias never been examined, and which require no very wonderful stretch of 

 ability to analyse. Why then cannot it be done in India as well as in 

 Europe. Mr. John Griffin, the translator of Rose, in a little work entitled 

 " Chemical Recreations," which is in fact a most excellent treatise on 

 operative chemistry, remarks that " No practical chemist, however young 

 ** he may be in the science, can pursue his studies with even a moderate 

 *' degree of zeal, without being enabled to add something almost daily 

 ** to the existing stock of knowledge. The variety of unrecorded facts 

 " which continually strike the eye of an industrious experimenter is 

 ** indeed surprising." Again.—" The notion that a laboratory, fitted 

 *' up with furnaces, and expensive and complicated instruments, is an 

 " absolute requisite for the proper performance of chemical experi- 

 ments, is exceedingly erroneous. In fact the truth is quite opposed 

 " to this opinion." — " For general and ordinary chemical purposes'* 

 says Dr. Henry " and even for the prosecution of new and important 

 *' enquiries, very simple means are sufficient; some of the most inter- 

 esting facts of the science may be exhibited and ascertained, with 

 the aid merely of florence flasks, of common phials, and of wine 

 glasses. In converting these to the purposes of apparatus, a consi- 

 ** derable saving of expence will accrue to the experimentalist : and he 

 " will avoid the encumbrance of various instruments, the value of which 

 consists in shew, rather than real utility. It is a curious and in- 

 *' structive fact, that some of the most important discoveries in che- 

 " mistry were made by persons who, either from choice or motives of 

 " economy, used utensils of the very simplest chi:.racters. The labora- 

 *' tory of the great Priestly cost a mere trifle ; and it is well known 

 how savingly Franklin went to work. The student will beware of 

 " procuring the large and showy apparatus which strike his eye from 

 <' the lecturer's table, for they are useless to him." These remarks 

 from a man of Mr. Griffin's practical experience, are encouraging enough 

 to the chemist in India, and shew how true the old adage is. " Where 

 there's a will, there*s a way." The Laboratory of Dr. W. Prout, one 



