70 SIXTH RKPORT— 1836. 



wliilc the risk of fracture was avoided. Then hy inverting the plate, 

 and holding the drops in succession some little height over the flame, 

 they became solutions of arsenious acid, and could be tested with the 

 three reagents as before stated. The part of the plate of mica con- 

 taining the crust may then be cut oif and introduced into glass tubes, 

 hermetically sealed up like the slips of blotting paper containing the 

 coloured results of the reagents. If it be necessary to malce quantita- 

 tive experiments, the products of the flame may be condensed in a 

 large globe ; the arsenious acid dissolved and precipitated by sulphu- 

 retted hydrogen. 



On Lithiate of Ammonia as a Secretion of Insects. By Wm. Hekapath. 



Lithic acid has been discovered as an abundant secretion in the urine 

 of mammalia, in that of birds (particularly of those with carnivorous 

 propensities), and in the excrement of the boa constrictor ; but Mr. H. 

 was not aware that it had been noticed among the insect tribes, previ- 

 ous to his examination of a fawn-coloured substance which is ejected 

 with considerable force by the common silk- worm (Phalcena Mori) in its 

 moth state of existence. This is principally composed of lithiate of 

 ammonia. As the insects do not eat either in the chrysalis or the moth 

 state, or even for some days before spinning, and as they discharge at the 

 last-mentioned period all the i-emains of food and become transparent, 

 it would seem that the lithiate of ammonia is not excrementitious in 

 the common acceptation of the term, but a secretion destined for some 

 particular purpose, possibly for softening the cocoon. He afterwards 

 examined other insects of the moth tribe, and found that there are so 

 many producing the same substance (varying a little in colour from the 

 presence of rosacic or purpuric acids) that it might be considered as 

 common to the tribe. Those who wish to carry on experiments upon 

 this point will find good subjects in the privet hawk-moth (Sphinx 

 ligustri), the lackey (Neustria), the puss vnoth. {Cerura vinula), and the 

 ermine. 



It is remarkable that in the cases mentioned by Mr. Herapath the 

 lithiate of ammonia should be produced by creatures living entirely on 

 vesretable food. 



Analysis of the IVater of the King's Bath, Bath. By Wm. Heeapath. 



Grains. 



On June 4th, 1836, the temperature of the spring head of the 

 King's Bath while running was 114° F., and its sp. gr. at 

 60° was 1001905 



Upon evaporating to dryness an imperial pint of 8750 gi's. 



the residue was found to be... . - 19"075 



A. — A little spirit of wine was three times aifused upon this 

 and decanted ; it had dissolved 3-23 grs. ; slow crystalliza- 

 tion under the microscope showed it to be chloride of mag- 

 nesium and chloride of sodium ; there was no chloride of 



