PHYSIOLOGICAL ACTION OF THE METHYL AND ALLIED SERIES. 407 



Section. I have grouped in these Tables certain representatives of different 

 series in their natural place and in five divisions, viz. nitrites, hydrides, 

 alcohols, chloi'ides, and iodides. Under each division the two first represen- 

 tatives of the series are tabled, and the fourth and fifth. The propylic com- 

 pounds, which would form the third representatives, are omitted in every case, 

 owing to the difficulty of obtaining perfectly reliable specimens. The sub- 

 stances named in italics have been considered in previous Eeports. 



While in this manner studying the various substances in great groups, I 

 have tried also to study peculiarities of action in members of the same group, 

 ■with special reference, in each case, to the effect of the aggregation of carbon 

 and increase of weight. 



To these observations I have been able to add others, which refer to the 

 individual peculiarities of some special compounds ; and when those peculia- 

 rities have suggested a practical and useful application, I have noted the facts 

 with care, and embodied them in my remarks. 



Lastly, as in the course of vay research many opportunities -were offered of 

 studying the dangers in the administration of some of the chemical bodies 

 named in the Table, I took advantage of such opportunities to test by experi- 

 ment the best means of counteracting those dangers when they occur. This 

 therefore forms a concluding and special part of the present Report. 



In preparing for experiments, certain rules were followed which it is right 

 at once to name. 



In all cases where the substance to be examined was a gas, it was adminis- 

 tered by inhalation ; in cases where the substance was a very volatile liquid, 

 it was administered by inhalation chiefly ; and in cases where the substance 

 was less easily volatilizable, it was administered not merely in the form of 

 vapour, but either by the mouth or by subcutaneous injection. 



