34 ANALYSIS OF PLANTS. 



consult the analyses, many of wliicli were timlertakcn wiili a view to tklonniiu' ihr law 

 of dislribiilion of the inorganic matter*. 



1 now propose to give in detail the resulu of the analyses which have been made in 

 furtherance of the objects of the Stale Survey. In doing this, I find it impossible to state 

 these details in that complete and perfect form wiiich is desirable. This arises from the 

 fact that the analyses ore still going on, will continue through this season, and can not be 

 completed till its close. What then remains, will be given in an appendix to this volume. 



The analysis of the ash of plants presents some difficulties which are not easily over- 

 come. The first step is to procure an ash in a proper condition : if it is highly alkaline, 

 it is very liable to fuse at low heal, and the fused particles embrace particles of coal, and 

 the ash is black. So it is liable to be caustic, or partly in a caustic state ; and hence there 

 will arise, in summing up the results, an apparent error : the figure will be too high, if 

 the carbonic acid is reckoned or calculated, instead of being obtained and weighed ; it will 

 be too low, if the carbonic acid is omitted. It is indeed difficult to obtain an ash entirely 

 free from this uncertainty. The ash of indian corn is the most difficult to obtain ; and, 

 besides this, I take it upon me to say, that up to this time, no one has yet made a correct 

 analysis of this grain, or without having too much loss. 



The method which I have pursued for the analysis of the ash of plants, has been the 

 one approved of by distinguished chemists. It has, however, been modified during the 

 progress of the work ; and if it has diflfered essentially from that of some distinguished 

 chemists, it has been for special reasons. 



I will now state the method which has been followed in the laboratory, in order tliat the 

 results may be appreciated. When the method of obtaining a result is defective, I have 

 no desire that it should pass for more than it is worth ; and as the results given have been 

 those which were actually obtained, it certainly is proper that the method also should be 

 known. It has not been my practice, nor that of my assistants, so far as I have known, 

 to distribute losses among the several results. The loss is a result as important as any, 

 and should be known, and never concealed, however great it may be. That a small loss 

 should occur, is inevitable; this will vary with the care bestowed, and the nature of the 

 substance analyzed. 



I. The preparation of tlie ash. The vegetable is burned at as low a temperature as pos- 

 ■ible, and sufficient time is given to consume the coal perfectly. Sometimes, however, 



* It k not intended here to claim the entire merit of determining the fact that the organs and parts of plants differ 

 in chemical constitution, and differ also in different periods of growth. That the kernel differed in composition from 

 the ftraw, has been known from the earliest times ; but the differences which are very constant in tlic ir.sidc and out- 

 ride wood of forest and fruit trees, the differences between the leaf and bark, the law of upward and outward move- 

 menti of the nutritive fluids, were, so far as I know, first observed in my laboratory. Our results, however, were not 

 published as early as some others bearing upon and proving the existence of the same general laws ; but I do not, 

 therefore, feel bound to credit discoveries in this field to others. By these remarks, it is not designed to claim more 

 than is my due, nor to withhold praise from others who have labored in the same field. The present period has been 

 remarkable for action and unremitting labors in the chemistry of plants, and many discoveries have been made almost 

 •imallaneouslv by different individuals. 



